Catalysis Weekly: Nat. Catal., JACS, Angew, AM, etc.

This tweet contains 25 articles, and the reading time is expected to be about 25 minutes. You can choose the ones you are interested in.

1. J. Am. Chem. Soc: Atomic In Catalysts for the Conversion of CO2 Electroreduction Products from Formate to CO

Electrochemical reduction of CO2 to chemicals and fuels is a way to reduce greenhouse gas emissions and energy shortages Fun and attractive approach. In this work, we report the electroreduction of CO2 to CO using an In atom catalyst. Atomic In catalysts were anchored on N-doped carbon (InA/NC) via the pyrolysis of In-based metal-organic frameworks (MOFs) and dicyandiamide . The study found that InA/NC has excellent performance for the selective preparation of CO in the ionic liquid/MeCN hybrid electrolyte. It is different from those common In-based materials that use formate/formic acid as the main product. The Faradaic efficiency (FE) and total current density of CO are 97.2% and 39.4 mA cm-2, respectively, and the transition frequency (TOF) is about 40,000 h-1. It has one of the highest CO yields among all catalysts reported so far. In addition, the catalyst also has excellent stability. Detailed investigations show that InA/NC exhibits high double-layer capacitance, large CO2 adsorption capacity, and low interfacial charge transfer resistance, resulting in high CO2 reduction activity. Control experiments and theoretical calculations show that the In-N sites in InA/NC not only facilitate the dissociation of COOH* to CO, but also hinder the formation of formate, resulting in high selectivity for CO rather than formate.

Original link:

https://doi.org/10.1021/jacs.1c00151

2. Zhongwei Chen JACS: "Two ships in a bottle" bimetallic catalyst design for highly selective and ultra-long-lasting CO2 electroreduction

Electrochemistry using renewable energy CO2 reduction (CO2RR) is a sustainable method for producing carbon-neutral fuels. Unfortunately, low energy efficiency, low product selectivity, and rapid deactivation are the most intractable challenges for CO2RR electrocatalysts.Here, we strategically propose a "two-boat-in-a-bottle" design for ternary Zn-Ag-O catalysts, in which ZnO and Ag phases are twinned to constitute a carbon matrix impregnated in ultra-high specific surface area A single ultrafine nanoparticle inside a nanopore. The electronic configuration of the bimetal can be tuned by constructing the Zn-Ag-O interface, in which the electron density reconfiguration induced by electron delocalization enhances the stability of the *COOH intermediate that is favorable for CO generation, while the rate-controlling step is altered by altering the stability of the *COOH intermediate. , making HCOO* form a high thermodynamic barrier, thereby promoting CO selectivity and suppressing HCOO formation. In addition, the shrinkage porosity mechanism limits the nanoscale size of bimetallic particles with abundant Zn-Ag-O heterointerfaces and exposed active sites, while suppressing the shedding and agglomeration of nanoparticles during CO2RR process, enhancing the stability . The designed catalyst exhibits an energy efficiency of 60.9% for CO, a Faradaic efficiency of 94.1±4.0%, and excellent stability over 6 days. Besides providing high-performance CO2RR electrocatalysts, this study also proposes a promising catalyst design strategy for energy-efficient conversion.

Original link:

https://doi.org/10.1021/jacs.0c12418

3. J. Am. Chem. Soc: Re-understanding of the electrochemical reduction of CO2 on Cu(111): Competing proton-coupled electrons revealed by embedded correlation wave function theory Shift Reaction Mechanism

Copper (Cu) electrodes serve as the most efficient electrocatalysts for the CO2 reduction reaction (CO2RR) and serve as a model for the determination and validation of the electrochemical CO2 reduction to hydrocarbons reaction mechanism. Since the in situ electrochemical mechanism cannot be determined experimentally, density functional theory (DFT) is usually used for mechanism analysis. Unfortunately, the semilocal exchange correlation (XC) approximation most commonly used to model such catalysis introduces a fundamental error: predicting the key intermediate in CO (CO2RR) on the most ubiquitous Cu face (i.e., Cu(111)) ) of the wrong adsorption sites.This long-standing inconsistency casts doubt on previous DFT predictions of CO2RR dynamics. In this paper, the embedded correlation wave function (ECW) theory, which corrects the error of the XC function, is applied to study CO2RR on Cu(111) by surface hydride (*H) transfer and proton-coupled electron transfer (PCET). We predict that the adsorbed CO (*CO) is almost equally reduced to two intermediates, hydroxymethylidyne (*COH) and formyl (*CHO) at 0.9 V compared to RHE. In contrast, the predictions of semi-local DFT approximations are more inclined towards *COH. As the applied potential increases, the dominance of *COH (formed via potential-independent surface *H transfer) diminishes in favor of the competing formation of *CHO and *COH (both via potential-dependent PCET formation). Our results also demonstrate the importance of explicitly modeling solvent molecules for predicting electron transfer barriers and reveal the shortcomings of simple surface *H transfer models that rely too heavily on reduction reactions.

Original link:

https://doi.org/10.1021/jacs.1c00880

4. Nat. Commun: On the limitations of using aqueous model electrochemical cells to assess the stability of oxygen evolution catalysts There is a severe deviation between the dissolution in the system and the membrane electrode assembly. This question calls into question the relevance of widely used real-world aqueous testing. In this study, we aimed to identify the processes responsible for differences in dissolution. The effects of experimental parameters known to diverge in both systems on the dissolution of Ir-based catalysts were tested separately. studies the dissolution of Ir in a water model system, which is a scanning flow cell coupled to an inductively coupled plasma mass spectrometer. The actual dissolution rate of the Ir OER catalyst in the membrane electrode assembly was measured by a specially developed dedicated setup. The acidity of the anode catalyst layer that is too high and the stability over time in the actual device are the main factors leading to the difference in dissolution.The results presented here provide clear guidelines for testing parameters of anode electrocatalysts under realistic electrolyzer operating conditions.

Original link:

https://doi.org/10.1038/s41467-021-22296-9

5. Adv. Funct. Mater: Pt single atoms immobilized on monolayer tungsten trioxide nanosheets as efficient electrocatalysts for hydrogen evolution reaction

Passed Single-layer WO3·H2O (ML-WO3·H2O) nanosheets were synthesized by a spatial confinement strategy, and then Pt single atoms (Pt-SA) were individually immobilized on the single-layer WO3 (ML-WO3) to construct a single-atom catalyst (SAC). ). Pt-SA/ML-WO3 retains the monolayer structure of ML-WO3·H2O, has a high monolayer ratio up to 93%, and is rich in defects (O and W vacancies). The catalyst exhibits excellent electrocatalytic performance with a low overpotential of -22 mV at a current of -10 mA cm-2, a high switching frequency of 87 H2S-1 site-1 at η = -50 mV, and long-term stability. Of particular note is its mass activity of 87 A mgPt-1 at η = −50 mV, which is 160 times that of the current state-of-the-art commercial catalyst, 20 wt% Pt/C (0.54 A mgPt-1). Experiments and DFT analysis show that its excellent performance comes from the strong synergistic effect between Pt single atoms and the carrier. This study provides an efficient route for large-scale preparation of ML-WO3 nanosheets, demonstrating that ML-WO3 is an excellent support for SACs, and also reveals the great potential of SACs in reducing the amount of noble metals in catalysts.

Original link:

https://doi.org/10.1002/adfm.202009770

6. ACS Catal: Electrochemical conversion of CO2 to CO2 on a single-atom tin catalyst in a non-nitrogen -coordinated environment under a wide potential window

with different coordination structures Replacing traditional metal-N4 coordination is a promising strategy to tune the activity and selectivity of single-atom catalysts (SACs).However, for metals such as tin (Sn)-driven CO2 electroreduction, which may generate multiple chemical species, the effect of the non-nitrogen coordination environment on the CO2 reduction pathway is unclear. In this paper, we report a Sn SAC with a special coordination structure Sn-C2O2F, which can reduce CO2 to a single product CO with a Faradaic efficiency higher than 90.0% (-0.2 to -0.6 V vs RHE) and peaked at 95.2%. The resulting cathode energy efficiency and current density of reached 70.7% and 186 mA cm-2, respectively. Instead, formate is mainly formed at the Sn-N4 site. Theoretical calculations show that the coordination of C and O regulates the adsorption of the intermediate, while the Sn-bonded F atom significantly suppresses hydrogen evolution, thereby promoting the conversion of CO2 to CO. Meanwhile, the conversion of CO2 to HCOO– or the direct reaction of absorbed H and dissolved CO2 via O-bound intermediates is also inhibited.

Original link:

https://doi.org/10.1021/acscatal.0c05514

7. Nat. Catal.: Visible-light-catalyzed dicarboxylation of olefins, propylene and (hetero)aromatics with CO2

By mimicking natural, light-driven carbon dioxide utilization It has broad prospects in organic synthesis. However, this conversion is limited to the incorporation of only a single CO2 molecule into organic compounds, far less than the number of CO2 molecules immobilized in the product of photosynthesis. This paper reports the visible light photocatalytic dicarboxylation of alkenes, alkenes and (hetero)arenes with two CO2 molecules. This method achieves the formation of multiple C-C bonds with high chemoselectivity and diastereoselectivity under mild conditions, which is a simple, rapid and sustainable method for the development of valuable dicarboxylic acids. The , -free transition metal method has the advantages of low catalyst loading, good tolerance to functional groups, wide substrate range, easy expansion and product derivatization.Mechanistic studies reveal that visible-light-induced two-electron reduction generates the radical anion of this unsaturated substrate via sequential single-electron transfer, broadening the scope of strategies.

Original link:

https://www.nature.com/articles/s41929-021-00594-1#auth-Da_Gang-Yu

8. J. Am. Chem. Soc.: Copper-mediated free radical-polarity crossover can Photocatalytic oxidative functionalization of sterically larger alkenes

Oxidative heterofunctionalization reactions are one of the most attractive methods to convert alkenes and heteroatom nucleophiles into complex saturated heterocyclic compounds. However, state-of-the-art transition metal catalysis methods affecting oxidative heterofunctionalization are generally limited to unhindered alkenes, and different nucleophilic partners often require quite different reaction conditions. Herein we report a Cu(II)-mediated radical polarity crossover allowing efficient and exceptionally mild photocatalytic oxidative heterofunctionalization between a large number of tri- and tetra-substituted alkenes and various nucleophilic partners. Furthermore, the authors demonstrate that the broad scope of this transformation results from photocatalytic olefin activation, thus complementing existing transition metal-catalyzed oxidative heterofunctionalization approaches. More broadly, these results further demonstrate that Cu(II) salts are ideal terminal oxidants for photodox applications, and that the combination of photocatalytic substrate activation and Cu(II)-mediated radical oxidation can address long-term existence in catalytic oxidation chemistry. challenge.

Original link:

https://pubs.acs.org/doi/10.1021/jacs.1c02747

9. J. Am. Chem. Soc.: Interfacial engineering of nanowire Bi19Br3S27 to promote metal photocatalytic CO2 reduction activity under near-infrared light

The development of efficient photocatalysts to convert carbon dioxide into solar fuels using solar radiation has important implications for energy sustainability and carbon neutrality. In this paper, a near-infrared (NIR) photoresponsive nanowire photocatalyst V-Bi19Br3S27 was prepared by alkaline etching and an interface reconstruction strategy. The as-prepared V-Bi19Br3S27 nanowires exhibited high-efficiency metal photocatalytic reduction performance for converting CO2 to CH3OH when excited alone under near-infrared illumination. In the absence of any cocatalysts and sacrificial agents, the CH3OH generation of metal-defective V-Bi19Br3S27 is 2.3 times higher than that of Bi19Br3S27 nanowires. The specific interfacial structure evolution and reaction mechanism have been carefully explained down to the atomic scale. This work provides a unique interface engineering strategy for the development of high-performance sulfur-based near-infrared photocatalysts for photon reduction of carbon dioxide to ethanol for high-value solar fuel chemicals, for efficient utilization of solar radiant energy extending into the near-infrared range, Achieving carbon neutrality goals paves the way.

Original link:

https://pubs.acs.org/doi/10.1021/jacs.1c01109

10. J. Am. Chem. Soc.: Gold Nanoparticle-Coated MOF Films for Direct Plasma Photocatalytic Nitrogen Fixation

Photocatalytic Nitrogen Fixation The reaction can harvest solar energy to convert abundant and inert N2 into NH3. In this paper, direct plasmonic photocatalytic nitrogen fixation under ambient conditions is realized by dispersing and confining gold nanoparticles (AuNPs) using metal-organic framework (MOF) films as ideal assemblies for nanoreactors. Under the irradiation of visible light, the hot electrons generated on the gold nanoparticles can be directly injected into the N2 molecules adsorbed on the gold surface. This N2 molecule can also be activated by a strong and localized surface plasmon resonance field, resulting in a superlinear intensity dependence of the ammonia precipitation rate with higher apparent quantum efficiency and lower apparent activation energy.In addition, the gas permeable Au@MOF membrane composed of numerous interconnected nanoreactors can ensure the dispersion and stability of AuNPs, which further facilitates the mass transfer of N2 molecules and (hydrated) protons, and facilitates the solution interface of the designed gas membrane. plasmonic photocatalytic reaction. The results show that the ammonia evolution rate is 18.9 mmol gAu-1 h-1 under visible light (>400 nm, 100 mw cm-2), and the apparent quantum efficiency at 520 nm is 1.54%.

Original link:

https://pubs.acs.org/doi/10.1021/jacs.0c13342

11. ACS Catal.: Rational Design of Single-Atom-Doped Ga2O3 Propane Dehydrogenation Catalysts

Volcano curves have been demonstrated in the field of heterogeneous catalysis Particularly useful in the design of new catalysts. On the other hand, for a given reaction, further improvements in optimized catalyst performance are inherently limited by the Sabatier principle. In this paper, the micro-kinetic analysis of the adsorption and catalytic behavior of the single-atom-doped Ga2O3 catalyst in propane dehydrogenation was carried out, and the results showed that the Lewis acid-base interaction can break through the volcano-like activity curve, which makes it possible Better catalytic performance than the most active catalyst near the top of the volcano is obtained. The reasoning behind this finding of is that the presence of Lewis acid-base interactions on the surface of metal oxides may enhance the coadsorption of a pair of amphiphilic species at M-O sites, resulting in markedly different chemisorption energies and transition state energy scaling relationships . The results show that the formation energies of the H&H co-adsorption at the M-O site and the formation energies of the OIMH adsorption in the presence and absence of Lewis acid-base interactions are two different reactivity descriptors, respectively, and their activity curves are linear and volcano curve.Further experiments verify that the theoretically predicted candidate catalyst Ir1-Ga2O3 is more efficient than the previously reported trace Pt-promoted Ga2O3 catalyst, opening a new avenue for the rational design of metal oxide catalysts in the PdH process.

Original link:

https://pubs.acs.org/doi/10.1021/acscatal.0c05454

12. Nat. Catal.: Regioirregularity and Catalytic Mizoroki-Heck Reaction Mizoroki-Heck reaction) is an efficient method to construct new carbon-carbon bonds. However, the success of this reaction is hampered to some extent by the extremely pronounced regioselectivity on the double bond, which determines that electron-deficient alkenes only react on the β-carbon. Here we demonstrate that ligand-free, few-atom palladium clusters in solution catalyze the α-selective intramolecular Mizoroki-Heck coupling of lipiodol cinnamate, and mechanistic studies support the formation of palladium cinnamate cluster intermediates. According to this principle, α-selective intermolecular coupling of aryl iodides to styrene is also achieved through palladium clusters encapsulated in finely tuned and sterically confined zeolite cavities to yield 1,1- Bisarylacetylenes, which are further combined with aryl halides via metal-free photooxidative catalytic coupling. These ligand-free approaches significantly expand the chemical space for Mizoroki-Heck couplings.

Original link:

https://www.nature.com/articles/s41929-021-00592-3

13. Angew. Chem. Int. Ed.: Origin of redox-active MOF-catalyzed C-H oxidation of benzyl groups

Usually using toxic or The selective oxidation of benzyl hydrocarbons to ketones using precious metal catalysts is very important for the production of various fine chemicals. This paper reports the efficient oxidation of benzyl C-H groups in a wide range of substrates under mild conditions on a robust metal-organic framework material, MFM170, containing a redox-active [Cu2II(O2CR)4] electrode . Using a comprehensive study of electron paramagnetic resonance (EPR) spectroscopy and synchrotron X-ray diffraction, identified the key to the activation of the oxidant tBuOOH (tert-butyl hydroperoxide) by the partial reduction of the paddle wheel to the [CuIICuI(O2CR)4] species effect.

Original link:

https://onlinelibrary.wiley.com/doi/10.1002/anie.202102313

14. Angew. Chem. Int. Ed.: Subsecond time-resolved surface-enhanced Raman spectroscopy reveals electrochemical CO2 reduction on copper Dynamic CO intermediates in the process

The electrocatalytic reduction of carbon dioxide (CO2) to value-added products such as ethylene is a promising approach to mitigate greenhouse gas emissions, but many details of the electrocatalytic CO2 reduction reaction (CO2RR) remain Not sure. Raman spectroscopy is suitable for in situ characterization of the CO2RR mechanism, but the low signal intensity and the resulting poor temporal resolution (usually up to minutes) hinder the application of traditional Raman spectroscopy techniques to the study of dynamic CO2 reduction reactions , which requires a temporal resolution of less than a second. By using time-resolved surface-enhanced Raman spectroscopy (TR-SERS), the authors were able to successfully monitor CO2RR on Cu surfaces with subsecond temporal resolution. Anodization at 1.55 V vs. reversible hydrogen electrode (RHE) and subsequent surface oxide reduction (below -0.4 V vs. RHE) resulted in roughening of the copper electrode surface, resulting in a TR-SERS hotspot, increasing the temporal resolution (down to ~0.7 s) and improved CO2RR efficiency (i.e., a fourfold increase in ethylene Faradaic efficiency). In TR-SERS, hot spots of SERS and CO2RR are formed initially (<7s),>

Original link:

https://doi.org/10.1002/anie.202104114

15. Angew. Chem. Int. Ed.: Combination of plasma oxidation and electrocatalytic reduction for efficient nitrogen fixation to ammonia

Nitrogen (N2) in the atmosphere to ammonia The transformation of (NH3) is a long-term pursuit of human beings. However, the current step-by-step N fixation is hindered by the strong activation of N≡N bonds and low selectivity to NH3. Here, the authors report that N2 to NH3 fixation can be efficiently decomposed into a two-step process, with each step independently and efficiently solving a problem, including:

1) Easy activation of N2 to NOx by non-thermal plasma techniques;

2) Highly selective conversion of NOx to NH3 by electrocatalytic reduction.

Importantly, the process uses air and water as low-cost feedstocks for scalable production of ammonia at ambient conditions. To reduce NOx to NH3, we propose a novel surface boron-rich core-shell nickel boride electrocatalyst. Combining a series of physical characterizations and in situ spectroscopic measurements, we found that the characterization of boron-rich surfaces is the key to improving activity, selectivity, and stability by enhancing NOx adsorption and suppressing hydrogen evolution and surface Ni oxidation. As a result, a high ammonia yield of 198.3 µmol h–1 cm–2 was achieved, as well as a Faradaic efficiency of nearly 100%.

Original link:

https://doi.org/10.1002/anie.202104394

16. Angew. Chem. Int. Ed.: Intrinsic Electrocatalytic Activity for Oxygen Evolution of Three-Dimensional Transition Metal Layered Double Hydroxides

Layered Double Hydroxide Lithium oxides (LDHs) are one of the most active oxygen evolution catalysts in alkaline electrolytes. However, previous studies have either focused on few-layer LDHs, applied synthetic routes with limited structural control, or used non-intrinsic activity indicators. This prevents building consistent structure-activity-relationships. Here, by employing a new individually developed synthetic strategy controlled by atomic structure, the authors obtained a broad series of crystalline α-MA(II)MB(III)LDH and β-MA(OH)2 electrocatalysts (MA=Ni , Co, MB = Co, Fe, Mn). The authors further obtained their intrinsic activities by normalizing the electrochemical active surface area, revealing their development trends: NiFe-LDH, CoFe-LDH, Fe-free-Co-containing catalysts, and Fe-Co-free Ni-based catalysts. Our theoretical reactivity model reveals that the intrinsic activity trends stem from the bimetallic site nature of the reaction center, which leads to compound-dependent synergy, and various scaling relationships that can be used to design higher-performing catalysts.

Original link:

https://doi.org/10.1002/anie.202100631

17. Angew. Chem. Int. Ed.: High-rate electroreduction of CO2 to C2+ products over copper-copper iodide catalysts

Electrochemical CO2 reduction Reaction (CO2-RR) to produce high-energy-density, high-availability hydrocarbons and oxygenates (C2+) is of great interest, providing a promising avenue to realize renewable energy storage and carbon cycling. Here, we design Cu-CuI composite catalysts with abundant Cu/Cu+ interfaces by physically mixing copper nanoparticles and CuI.Compared with the reversible hydrogen electrode in the flow cell, the composite catalyst achieves a remarkable C2+ local current density of 591 mA cm−2 at −1.0 V, which is much higher than that of Cu (329 mA cm−2) and CuI (96 mA cm−2). 2) The corresponding local current density. Under the induction of alkaline electrolyte and applied potential, the Cu-CuI composite catalyst undergoes remarkable reconfiguration under CO2-RR conditions. Structural characterization and theoretical calculations suggest that the high C2+ generation rate on Cu-CuI is attributed to the presence of residual Cu+ and adsorbed iodine species, which improve CO adsorption and facilitate C-C coupling.

Original link:

https://doi.org/10.1002/anie.202102657

18. Angew. Chem. Int. Ed.: Atomic Sulfur Filling Oxygen Vacancies Optimizes Hydrogen Absorption and Promotes Hydrogen Evolution in Alkaline Media

In Alkaline Solution , the hydrogen evolution reaction is usually kinetically slow due to the difficulty in forming bound protons. This paper reports an electrocatalyst with active centers with enhanced electron transfer capability by doping sulfur atoms into oxygen vacancies (VO) of inverse spinel NiFe2O4 (S‐NiFe2O4). Our results show that this electrocatalyst exhibits an ultralow overpotential of 61 mV at a current density of 10 mA cm-2 and a long-term stability of 60 h at 1.0 A cm-2 in 1.0 M KOH medium. After coupling with VO, the highly electroactive S atom helps to bond with protons. In situ Raman spectroscopy revealed that the S site absorbs hydrogen atoms (H*) and forms S-H* in situ, which favors hydrogen production and enhances HER in alkaline solutions. DFT calculations further verified the lowering of the energy barrier for HO dissociation caused by S introduction, which is a key factor leading to its remarkable performance improvement. Both experimental and theoretical studies have confirmed that S atom is the active center of NiFe2O4. This work provides a simple and efficient solution for designing novel electrocatalysts to accelerate water splitting through a vacancy-filling strategy.

Original link:

https://doi.org/10.1002/anie.202104055

19. Angew. Chem. Int. Ed.: Interaction of visible light with iron to catalyze the formation of nitrobenes and conversion of dioxazolones

This paper describes the use of visible light The driven iron-catalyzed nitrene transfer reaction with bisoxazolones undergoes intermolecular C(sp3)-N, N=S, and N=P bond formation. These reactions were performed using an exogenous ligand-free process with good yields (up to 99%) and broad substrate availability (109 examples) under mild reaction conditions. Different from the intramolecular C−H amidation strategy, we designed intermolecular regioselective C−H amidation via visible light-induced nitrene transfer reaction. Mechanistic studies show that the reaction proceeds through a free radical pathway. Computational studies show that the decarboxylation reaction of bisoxazolones relies on the transformation of the sixfold ground state bisoxazolone-bound iron species to the quadruple spin state by visible light irradiation.

Original link:

https://doi.org/10.1002/anie.202016234

20. Angew. Chem. Int. Ed.: Influence of external surface diffusion barrier on Pt/β-catalyzed -n-pentane isomerization

zeolite The outer surface of the crystal contains transport barriers that hinder the uptake of molecules and processes that depend on it, such as catalysis and separation. However, the potential dominant role of surface barriers in such processes is only just emerging. In this work, the authors developed a general strategy to quantify the effect of surface barriers on zeolite catalysis. The isomerization of n-pentane catalyzed by Pt/β was used as a model reaction system. First, zeolite beta was surface-modified by chemical liquid deposition to control its surface barrier. The deposition of SiO2 resulted in a small change in the physical properties of β crystals, but a marked reduction in brnsted acid sites.The apparent diffusion coefficient of n-pentane after SiO2 deposition was measured by the zero-length column (ZLC) method, and the results showed that the apparent diffusion coefficient of n-pentane after SiO2 deposition more than doubled, indicating a weakening of the surface barrier. The catalytic performance was tested in a fixed-bed reactor, and the results showed that the apparent catalytic activity after SiO2 deposition was increased by 51-131%. These results directly demonstrate that reducing the surface barrier is an effective way to improve the performance of molecular sieve catalysts.

Original link:

https://doi.org/10.1002/anie.202104859

1. Adv. Funct. Mater.: Anions at the Atomic Scale Constructing Anti-Perovskite Crystals for Electrochemical Reactions

Palladium as Platinum in Platinum Group Metals The alternatives to are considered to be the most efficient electrocatalysts. Although the electrochemical activities of Pd and Pd-metal alloys are comparable, they are susceptible to the influence of liquid acidic electrolytes, leading to a decrease in catalytic activity. Since the electronic structure of palladium can be easily changed, palladium-nickel alloys are used to improve the catalytic activity. In other studies, N atoms were introduced into more stable M-Ni catalysts by inducing the formation of Ni4N species; however, the structural analysis and role of nitrogen have not been fully understood. In this study, it was found that the Pd–Ni alloy nitrides with unique crystal structure have good catalytic activity for oxygen reduction reaction (ORR). Nitride PdNi nanoparticles have a novel monolithic anti-perovskite structure with the chemical formula (PdxNi1−x)NNi3. The unique anti-perovskite crystal (PdxNi1−x) NNi3 exhibits excellent ORR activity and stability, which originates from the downshift of the d-band center on the surface of the monolayer Pd/anti-perovskite and the comparison of the anti-perovskite core nanocrystals. Low energy of formation. Therefore, (PdxNi1−x)NNi3, as a platinum-free Pd-based electrocatalyst, overcomes the stability problem of Pd under acidic conditions in durability tests by achieving a mass activity 99 times higher than that of commercial Pd/C.

Original link:

https://onlinelibrary.wiley.com/doi/10.1002/adfm.202009241

22. ACS Catal.: Organometallic Pd(III) complexes realize electrocatalytic reduction of O2 through dinuclear Pd(III) intermediates

Developed Electrocatalysts for the selective conversion of O2 to H2O, i.e., the O2 reduction reaction (ORR), are of great significance for improving the performance of fuel cells. Molecular catalysts are known to mediate 4H+/4e– in controlled multiproton and multielectron transfer steps, with limited stability and selectivity for the reduction of O2 to H2O. Therefore, evaluating the ORR activity of transition metal complexes, including organometallic species, can uncover molecular catalysts with improved properties. Synthesis and characterization of various organometallic PdIII complexes stabilized by the tetradentate ligand N,N have been reported'-di-tert-butyl-2,11-diazo[3.3](2,6)pyridinol (tBuN4) . The results show that these complexes can react with O2 and undergo oxidation-induced heteroatom bond formation reactions in the presence of C–C and C–oxygen. The ORR activity of this organometallic palladium complex was assessed by these oxygen-induced oxidative transformations, which has never been studied on any molecular palladium catalyst. Here, we report the ORR reactivity of [(tBuN4))PdIIIMeCl]+ complexes in non-aqueous and acidic aqueous electrolytes under homogeneous and heterogeneous conditions. Cyclic voltammetry and hydrodynamic electrochemical studies of [(tBuN4))PdIIIMeCl]+ showed that the Faradaic efficiencies (FEs) for the electrocatalytic reduction of O2 to H2O were 50–70% when acetic acid (AcOH) was added to MeCN. In an acidic aqueous medium (pH 0), the molecular catalysts were immobilized on edge plane graphite (EPG) electrodes, and the selectivity for HO generation was further improved to 80–90% FE. Electrochemical data analysis indicates the formation of a binuclear PdIII intermediate in solution, most likely a PdIII peroxyPdIII species, which determines the thermochemistry of the ORR process of [(tBuN4))PdIIIMeCl]+ in MeCN, a rarity for bimolecular ORR processes example.In O2-saturated MeCN with an overpotential of 0.32 V, the maximum second-order turnover frequency of 0.32 mM [(tBuN4)PdIIIMeCl]+ in O2-saturated MeCN at 1 M AcOH is TOFmax2 = 2.76 × 108 M–1S–1. In contrast, with a relatively low TOFmax2 = 1.25 × 105 M–1S–1 in oxygen-saturated 1 M H2SO4 aqueous solution, [(tBuN4))PdIIIMeCl]+PF6 was observed at a higher overpotential of 0.8 V adsorbed on the EPG electrode. Overall, this article reports a detailed ORR reactivity using PdIII organometallic complexes to test their selectivity and energetics for MeCN and O2 reduction in acidic aqueous solutions.

Original link:

https://pubs.acs.org/doi/10.1021/acscatal.0c05726

23. Adv. Mater.: Preparation of Ta3O7F and TaO2F with High Photocatalytic OER Activity by Fluorinated Metal Oxides by Spark Plasma Sintering General method for treating metal oxides by spark plasma sintering (SPS) of tetrafluoroethylene (PTFE, Teflon) waste. Its application potential is as follows:

i) Tantalum oxide fluoride Ta3O7F and TaO2F are obtained from plastic waste and are not fluorinated using toxic or corrosive chemicals.

ii) Shorter response times (minutes instead of days) reduce process time and energy costs by nearly three orders of magnitude.

iii) The oxide fluorides Ta3O7F and TaO2F are produced in gram quantities of nanoparticles. With industrial sintering equipment, its synthesis amount can be increased to kg.

iv) SPS treatment changed the catalytic performance: Although the traditionally prepared Ta3O7F and TaO2F had almost no catalytic activity, the SPS-prepared Ta3O7F and TaO2F exhibited high photocatalytic oxygen evolution activity, reaching a photoconversion efficiency of 24.7% and a photoconversion efficiency of 0.86%. The light conversion bias value.

This study shows that the properties of materials depend on the processing process, which suggests new directions for understanding and predicting underlying factors.

Original link:

https://onlinelibrary.wiley.com/doi/10.1002/adma.202007434

24. Adv. Funct. Mater.: Ni1−xCoxSe2-C/ZnIn2S4 hybrid nanometers with strong 2D/2D heterointerface interactions Cages are used for efficient photocatalytic hydrogen evolution

Based heterostructure photocatalysts based on semiconductors to achieve efficient separation of photogenerated electrons are of great significance to improve the efficiency of photocatalytic hydrogen evolution. In this paper, we propose a novel Ni1−xCoxSe2-C/ZnIn2S4 multilayer nanocages with abundant and dense ZnIn2S4 nanosheets/Ni1−xCoxSe2-type 2D/2D heterointerfaces. The constructed heterostructured photocatalysts expose abundant heterostructures-providing broad and short transport paths for charge carriers. The close contact of these two nanosheets resulted in a strong interaction between ZnIn2S4 and Ni1−xCoxSe2-C, as well as improved separation and transfer of light-generated electron-hole pairs. The results show that the Ni1−xCoxSe2-C/ZnIn2S4 multilayer nanocages do not require additional noble-metal cocatalysts, and the hydrogen evolution rate under visible light irradiation is 5.10 mmolg-1h-1, which is comparable to that of ZnIn2S4 nanosheets and bare Ni1−xCoxSe2-C/ Compared with the nanocages, they are 6.2 times and 30 times higher, respectively. Spectral characterization and theoretical calculations indicate that the strong interaction between ZnIn2S4 and Ni1−xCoxSe2-C strongly promotes the separation of photogenerated carriers and the transfer of electrons from ZnIn2S4 to Ni1−xCoxSe2-C.

Original link:

https://onlinelibrary.wiley.com/doi/10.1002/adfm.202100923

25. Nat. Commun.: Analysis of SAPO-34/18 intermolecular symbiosis through identification of light atoms and bonds for methanol conversion

The microstructure of a catalyst material directly affects its macrostructure and catalytic performance. Molecular sieve catalysts are widely used in methanol conversion processes, and atomic analysis of their microstructures will give us a deeper understanding of their structure-property relationships.However, atomic imaging of silicoaluminophosphate molecular sieves with the electron microscope remains challenging due to the limitation of its electron beam sensitivity. In this study, real-space imaging of atomic lattices, including Al–O–P atoms and bonds, in SAPO-34 and SAPO-18 molecular sieves was achieved by integrated differential phase contrast scanning transmission electron microscopy (iDPC-STEM). The spatial distribution of SAPO-34 and SAPO-18 domains in the SAPO-34/18 symbiont can be clearly resolved. By varying the Si content and templating agent in the feedstock, two SAPO-34/18 catalysts, namely hierarchical catalysts and sandwich-structured catalysts, were obtained with highly mixed and separated SAPO-34 and SAPO-18 lattices, respectively. The reduction of the inner product diffusion distance greatly improves the catalytic performance of the two catalysts in methanol conversion. Based on the observed lattice and distribution of elements in these catalysts, a preliminary understanding of the interrelationship between the synthesis conditions and structures of the SAPO-34/18 intergrowth catalyst can be obtained, thereby further improving its performance according to its unique structure.

Original link:

https://www.nature.com/articles/s41467-021-22438-z