Controllable selective anchoring of subnanometric Ru clusters or single-atoms/clusters on tungsten nitride for the hydrogen oxidation

The impregnation method in the preparation of metal cluster catalysts typically inadvertently introduces single atoms(SAs) into the substrate. However, the question of whether the introduction of SAs will further improve the catalytic activity of cluster systems for specific reactions such as the hydrogen oxidation reaction(HOR) remains unraveled. Herein, we demonstrate Ru clusters anchored on WN nanowires(RuC/WN) show a higher alkaline HOR catalytic activity in comparison with Ru SAs and nanoclusters(NCs)-coupled catalyst anchored on WN nanowires system(RuC,S/WN). Notably, the RuC/WN exhibits superb intrinsic catalytic activity with a mass-normalized exchange current density of 890 m A mg^(-1)PGM, which is among the top level of well developed Ru-based HOR catalysts. Both theoretical simulation and experimental investigation suggest that RuC/WN owns an optimized H^(*)and OH^(*) reaction intermediates for the alkaline HOR, therefore resulting in the excellent intrinsic HOR catalytic performance.

High-Performance H_(2) Photosynthesis from Pure Water over Ru−S Charge Transfer Channels

As a versatile energy carrier,H_(2) is considered as one of the most promising sources of clean energy to tackle the current energy crisis and environmental concerns,which can be produced from photocatalytic water splitting.However,solar-driven photocatalytic H_(2) production from pure water in the absence of sacrificial reagents remains a great challenge.Herein,we demonstrate that the incorporation of Ru single atoms(SAs)into ZnIn_(2)S_(4)(Ru-ZIS)can enhance the light absorption,reduce the energy barriers for water dissociation,and construct a channel(Ru-S)for separating photogenerated electron−hole pairs,as a result of a significantly enhanced photocatalytic water splitting process.Impressively,the productivity of H_(2) reaches 735.2μmol g^(-1) h^(-1) under visible light irradiation in the absence of sacrificial agents.The apparent quantum efficiency(AQE)for H_(2) evolution reaches 7.5% at 420 nm,with a solarto-hydrogen(STH)efficiency of 0.58%,which is much higher than the value of natural synthetic plants(~0.10%).Moreover,Ru-ZIS exhibits steady productivity of H_(2) even after exposure to ambient conditions for 330 days.This work provides a unique strategy for constructing charge transfer channels to promote the separation of photogenerated electron−hole pairs,which may motivate the fundamental researches on catalyst design for photocatalysis and beyond.

Atomically Dispersed Ru-Decorated TiO_(2) Nanosheets for Thermally Assisted Solar-Driven Nitrogen Oxidation into Nitric Oxide

Thermally assisted photodriven nitrogen oxidation to nitric oxide(NO)using air as a reactant is a promising way to supersede the traditional NO synthesis industry accompanied by huge energy expenditure and greenhouse gas emission.Meanwhile,breaking the N≡N triple bond(941 kJ·mol^(−1))in nitrogen is still challenging,and the development of more efficient catalysts is necessary.Herein,Ru single atoms decorated TiO_(2) nanosheets(Ru SAs/TiO_(2))were constructed and achieved superior performance for NO photosynthesis with a product rate of 192μmol g^(−1) h^(−1) and a quantum efficiency of 0.77% at 365 nm.Both ^(15)N isotope labeling experiments and in situ near ambient pressure X-ray photoelectron spectroscopy(in situ NAP-XPS)proved the origin of NO from N_(2) photooxidation.A series of in situ characterizations and theoretical calculations unveiled the reaction pathway of nitrogen photooxidation.Breaking the O-O bond to form(N-O)2-Ru intermediates was demonstrated as the rate-determining step.Importantly,a single-atomic structure was proven to inhibit the aggregation and inactivation of Ru,leading to outstanding durability.

Micropore-confined Ru nanoclusters catalyst for efficient pHuniversal hydrogen evolution reaction

Pt-based catalysts are used commercially for the hydrogen evolution reaction(HER),even though the low earth abundance and high cost of platinum hinder scale-up applications.Ru metal is a promising alternative catalyst for HER owing to its lower cost but similar metal-hydrogen bond strength to Pt.However,designing an efficient and robust Ru-based electrocatalyst for pHuniversal HER is challenging.Herein,we successfully synthesized N-doped carbon(NC)supported ruthenium catalysts with different Ru sizes(single-atoms,nanoclusters and nanoparticles),and then systematically evaluated their performance for HER.Among these catalysts,the Ru nanocluster catalyst(Ru NCs/NC)displayed optimal catalytic performance with overpotentials of only 14,30,and 32 mV(at 10 mA·cm^(-2))in 1 M KOH,1 M phosphate buffer saline(PBS),and 0.5 M H_(2)SO_(4),respectively.The corresponding mass activities were 32.2,12.1 and 8.1 times higher than those of 20 wt.%Pt/C,and also much better than those of the Ru single-atoms(Ru SAs/NC)and Ru nanoparticle(Ru NPs/NC)catalysts,at an overpotential of 100 mV under alkaline,neutral and acidic conditions,respectively.Density functional theory(DFT)calculations revealed that the outstanding HER performance of the Ru NCs/NC catalyst resulted from a strong interaction between the Ru nanoclusters and the N-doped carbon support,which downshifted the d-band center and thus weakened the*H adsorption ability of Ru sites.

Ru single atoms induce surface-mediated discharge in Na-O_(2)batteries

Sodium(Na)O_(2)batteries have high energy density and low cost.However,high polarization,complex discharge products,and low Coulombic efficiency(CE)lead to poor cyclability.Here,we proposed an atomically dispersed Ru catalyst on nitrogen-doped graphene for Na-O_(2)batteries.The catalysts enable the discharge to proceed via a surface-mediated route,which leads to uniform deposition of Na_(2-x)O_(2)and low polarization during recharge.The first-principle calculation revealed that Ru-N_(4)complex in the catalyst has strong chemical adsorption to intermediate superoxides,facilitating uniform deposition and enhancing rapid kinetics.In contrast,Ru nanoparticles,despite the catalytic activity,induce bulk deposition via a solution-mediated route because the exposed graphene surface shows weak interaction to superoxides,thereby lowering CEs and cyclability.In brief,the atomically-dispersed Ru catalyst endows Na-O_(2)batteries with excellent electrochemical properties via a surface-mediated discharge.