Core@shell structured Au@Sn O2 nanoparticles with improved N2 adsorption/activation and electrical conductivity for efficient N2 fixation

Au/SnO2核/壳纳米颗粒实现电化学高效固氮

The design of electrocatalysts with enhanced adsorption and activation of nitrogen(N2)is critical for boosting the electrochemical N2reduction(ENR).Herein,we developed an efficient strategy to facilitate N2 adsorption and activation for N2 electroreduction into ammonia(NH3)by vacancy engineering of core@shell structured Au@Sn O2 nanoparticles(NPs).We found that the ultrathin amorphous SnO2 shell with enriched oxygen vacancies was conducive to adsorb N2as well as promoted the N2 activation,meanwhile the metallic Au core ensured the good electrical conductivity for accelerating electrons transport during the electrochemical N2 reduction reaction,synergistically boosting the N2 electroreduction catalysis.As confirmed by the15N-labeling and controlled experiments,the core@shell Au@amorphous SnO2 NPs with abundant oxygen vacancies show the best performance for N2 electroreduction with the NH3 yield rate of 21.9 lg h-1mg-1catand faradaic efficiency of 15.2%at-10.2 VRHE,which surpass the Au@crystalline SnO2 NPs,individual Au NPs and all reported Au-based catalysts for ENR.

提升催化剂对氮气的吸附与活化是设计高效电化学固氮催化剂的关键.本文开发了一种提升电化学固氮手段,通过调控Au@SnO2核/壳纳米颗粒表面的氧空位,成功实现了将氮气有效电催化还原为氨.研究表明,Au@SnO2核/壳结构具有优异的导电性,同时能够增强氮气吸附与活化,在二者协同作用下实现了电化学高效固氮.其氨产率和法拉第效率在-0.2 V(vs.RHE)下分别可达21.9μg h-1 mg-1cat和15.2%,性能优于许多已报道的金基电催化剂.