Cr dopant mediates hydroxyl spillover on RuO for high-efficiency proton exchange membrane electrolysis.

Simultaneously improving the activity and stability of catalysts for anodic oxygen evolution reaction (OER) in proton exchange membrane water electrolysis (PEMWE) remains a notable challenge. Here, we report a chromium-doped ruthenium dioxide with oxygen vacancies, termed CrRuO, that drives OER with an overpotential of 170 mV at 10 mA cm and operates stably over 2000 h in acidic media. Experimental and theoretical studies show that the synergy of Cr dopant and oxygen vacancy induces an unconventional dopant-mediated hydroxyl spillover mechanism.

Nitrogen-Mediated Promotion of Cobalt-Based Oxygen Evolution Catalyst for Practical Anion-Exchange Membrane Electrolysis.

Scarce and expensive iridium oxide is still the cornerstone catalyst of polymer-electrolyte membrane electrolyzers for green hydrogen production because of its exceptional stability under industrially relevant oxygen evolution reaction (OER) conditions. Earth-abundant transition metal oxides used for this task, however, show poor long-term stability. We demonstrate here the use of nitrogen-doped cobalt oxide as an effective iridium substitute.

Facet-switching of rate-determining step on copper in CO-to-ethylene electroreduction.

Reduction of carbon dioxide (CO) by renewable electricity to produce multicarbon chemicals, such as ethylene (CH), continues to be a challenge because of insufficient Faradaic efficiency, low production rates, and complex mechanistic pathways. Here, we report that the rate-determining steps (RDS) on common copper (Cu) surfaces diverge in CO electroreduction, leading to distinct catalytic performances. Through a combination of experimental and computational studies, we reveal that C─C bond-making is the RDS on Cu(100), whereas the protonation of *CO with adsorbed water becomes rate-limiting on Cu(111) with a higher energy barrier.

Unraveling Stoichiometry Effect in Nickel-Tungsten Alloys for Efficient Hydrogen Oxidation Catalysis in Alkaline Electrolytes.

Anion-exchange membrane fuel cells provide the possibility to use platinum group metal-free catalysts, but the anodic hydrogen oxidation reaction (HOR) suffers from sluggish kinetics and its source is still debated. Here, over nickel-tungsten (Ni-W) alloy catalysts, we show that the Ni : W ratio greatly governs the HOR performance in alkaline electrolyte. Experimental and theoretical studies unravel that alloying with W can tune the unpaired electrons in Ni, tailoring the potential of zero charge and the catalytic surface to favor hydroxyl adsorption (OH).

Efficient and stable acidic CO electrolysis to formic acid by a reservoir structure design.

Electrochemical synthesis of valuable chemicals and feedstocks through carbon dioxide (CO) reduction in acidic electrolytes can surmount the considerable CO loss in alkaline and neutral conditions. However, achieving high productivity, while operating steadily in acidic electrolytes, remains a big challenge owing to the severe competing hydrogen evolution reaction. Here, we show that vertically grown bismuth nanosheets on a gas-diffusion layer can create numerous cavities as electrolyte reservoirs, which confine in situ-generated hydroxide and potassium ions and limit inward proton diffusion, producing locally alkaline environments.

Gerhardtite as a Precursor to an Efficient CO-to-Acetate Electroreduction Catalyst.

Carbon-carbon coupling electrochemistry on a conventional copper (Cu) catalyst still undergoes low selectivity among many different multicarbon (C) chemicals, posing a grand challenge to achieve a single C product. Here, we demonstrate a laser irradiation synthesis of a gerhardtite mineral, Cu(OH)NO, as a catalyst precursor to make a Cu catalyst with abundant stacking faults under reducing conditions. Such structural perturbation modulates electronic microenvironments of Cu, leading to improved d-electron back-donation to the antibonding orbital of *CO intermediates and thus strengthening *CO adsorption.

Efficient NH-Tolerant Nickel-Based Hydrogen Oxidation Catalyst for Anion Exchange Membrane Fuel Cells.

Converting hydrogen chemical energy into electrical energy by fuel cells offers high efficiencies and environmental advantages, but ultrapure hydrogen (over 99.97%) is required; otherwise, the electrode catalysts, typically platinum on carbon (Pt/C), will be poisoned by impurity gases such as ammonia (NH). Here we demonstrate remarkable NH resistivity over a nickel-molybdenum alloy (MoNi) modulated by chromium (Cr) dopants.

Enrichment of reactants and intermediates for electrocatalytic CO reduction.

The electrocatalytic carbon dioxide reduction reaction (CORR) presents a sustainable route to convert renewable electricity to value-added fuels and feedstocks in the form of chemical energy. However, the selectivity and rate of conversion of CO to desirable carbon-based products, especially multicarbon products, remain below the requirement for its implementation at the commercial scale, which primarily originates from inadequate reactants and intermediates near catalytic surfaces during the CORR. The enrichment of reactants and intermediates provides one of the coping guidelines to improve CORR performance by accelerating the reaction rate and improving product selectivity.

Design Principles for Maximizing Hole Utilization of Semiconductor Quantum Wires toward Efficient Photocatalysis.

Maximizing hole-transfer kinetics-usually a rate-determining step in semiconductor-based artificial photosynthesis-is pivotal for simultaneously enabling high-efficiency solar hydrogen production and hole utilization. However, this remains elusive yet as efforts are largely focused on optimizing the electron-involved half-reactions only by empirically employing sacrificial electron donors (SEDs) to consume the wasted holes. Using high-quality ZnSe quantum wires as models, we show that how hole-transfer processes in different SEDs affect their photocatalytic performances.

Nickel-Based Anode Catalysts for Efficient and Affordable Anion-Exchange Membrane Fuel Cells.

ConspectusLow-temperature ion-exchange membrane hydrogen fuel cells, as zero-emission power sources, can largely preserve the merits of gasoline engines, including rapid fueling, extended cruising range, and low maintenance cost. To enable the widespread prevalence of fuel-cell automobiles, the U.S.

Dopant triggered atomic configuration activates water splitting to hydrogen.

Finding highly efficient hydrogen evolution reaction (HER) catalysts is pertinent to the ultimate goal of transformation into a net-zero carbon emission society. The design principles for such HER catalysts lie in the well-known structure-property relationship, which guides the synthesis procedure that creates catalyst with target properties such as catalytic activity. Here we report a general strategy to synthesize 10 kinds of single-atom-doped CoSe-DETA (DETA = diethylenetriamine) nanobelts.

Nanosecond Laser Confined Bismuth Moiety with Tunable Structures on Graphene for Carbon Dioxide Reduction.

Substrate-supported catalysts with atomically dispersed metal centers are promising for driving the carbon dioxide reduction reaction (CORR) to produce value-added chemicals; however, regulating the size of exposed catalysts and optimizing their coordination chemistry remain challenging. In this study, we have devised a simple and versatile high-energy pulsed laser method for the enrichment of a Bi "single atom" (SA) with a controlled first coordination sphere on a time scale of nanoseconds. We identify the mechanistic bifurcation routes over a Bi SA that selectively produce either formate or syngas when bound to C or N atoms, respectively.

Dual Integrating Oxygen and Sulphur on Surface of CoTe Nanorods Triggers Enhanced Oxygen Evolution Reaction.

The bottleneck of large-scale implementation of electrocatalytic water-splitting technology lies in lacking inexpensive, efficient, and durable catalysts to accelerate the sluggish oxygen evolution reaction kinetics. Owing to more metallic features, transition metal telluride (TMT) with good electronic conductivity holds promising potential as an ideal type of electrocatalysts for oxygen evolution reaction (OER), whereas most TMTs reported up to now still show unsatisfactory OER performance that is far below corresponding sulfide and selenide counterparts. Here, the activation and stabilization of cobalt telluride (CoTe) nanoarrays toward OER through dual integration of sulfur (S) doping and surface oxidization is reported.

Interfacial Engineering of Ni/V O Heterostructure Catalyst for Boosting Hydrogen Oxidation Reaction in Alkaline Electrolytes.

Alkaline fuel cells can permit the adoption of platinum group metal-free (PGM-free) catalysts and cheap bipolar plates, thus further lowering the cost. With the exploration of PGM-free hydrogen oxidation reaction (HOR) catalysts, nickel-based compounds have been considered as the most promising HOR catalysts in alkali. Here we report an interfacial engineering through the formation of nickel-vanadium oxide (Ni/V O ) heterostructures to activate Ni for efficient HOR catalysis in alkali.

Theory-Guided Modulation of Optimal Silver Nanoclusters toward Efficient CO Electroreduction.

Electrochemical CO reduction reaction (CORR), when powered with intermittent but renewable energies, holds an attractive potential to close the anthropogenic carbon cycle through efficiently converting the exorbitantly discharged CO to value-added fuels and/or chemicals and consequently reduce the greenhouse gas emission. Through systematically integrating the density functional theory calculations, the modeling statistics of various proportions of CORR-preferred electroactive sites, and the theoretical work function results, it is found that the crystallographically unambiguous Ag nanoclusters (NCs) hold a high possibility to enable an outstanding CORR performance, particularly at an optimal size of around 2 nm. Motivated by this, homogeneously well-distributed ultrasmall Ag NCs with an average size of ∼2 nm (2 nm Ag NCs) were thus synthesized to electrochemically promote CORR, and the results demonstrate that the 2 nm Ag NCs are able to achieve a significantly larger CO partial current density [], an impressively higher CO Faraday efficiency of over 93.

Black Phosphorous Mediates Surface Charge Redistribution of CoSe for Electrochemical H O Production in Acidic Electrolytes.

Electrochemical generation of hydrogen peroxide (H O ) by two-electron oxygen reduction offers a green method to mitigate the current dependence on the energy-intensive anthraquinone process, promising its on-site applications. Unfortunately, in alkaline environments, H O is not stable and undergoes rapid decomposition. Making H O in acidic electrolytes can prevent its decomposition, but choices of active, stable, and selective electrocatalysts are significantly limited.

Boosting the stability of perovskites with exsolved nanoparticles by B-site supplement mechanism.

Perovskites with exsolved nanoparticles (P-eNs) have immense potentials for carbon dioxide (CO) reduction in solid oxide electrolysis cell. Despite the recent achievements in promoting the B-site cation exsolution for enhanced catalytic activities, the unsatisfactory stability of P-eNs at high voltages greatly impedes their practical applications and this issue has not been elucidated. In this study, we reveal that the formation of B-site vacancies in perovskite scaffold is the major contributor to the degradation of P-eNs; we then address this issue by fine-regulating the B-site supplement of the reduced SrFeNiMoO using foreign Fe sources, achieving a robust perovskite scaffold and prolonged stability performance.

General Synthesis of Tube-like Nanostructured Perovskite Oxides with Tunable Transition Metal-Oxygen Covalency for Efficient Water Electrooxidation in Neutral Media.

Hydrogen production from water electrolysis in neutral-pH electrolytes can not only avoid the corrosion and safety issues and expand the catalyst option but also potentially integrate with artificial photosynthesis and bioelectrocatalysis. However, heterogeneous catalysts that can efficiently negotiate the sluggish oxygen evolution reaction (OER) in neutral solutions are considerably lacking. Herein, we report a template-assisted strategy for the synthesis of 13 kinds of tube-like nanostructured perovskite oxides (TNPOs) with markedly high Brunauer-Emmett-Teller surface areas.