Recent progress of iron-based electrocatalysts for nitrogen reduction reaction

Ammonia is a critical feedstock for modern industry and agriculture,which is also a promising carbonfree energy carrier.Electrochemical nitrogen reduction reaction(ENRR)is a sustainable and efficient approach to synthesize ammonia under ambient reaction conditions.ENRR relies on the development of highly efficient electrocatalysts.So far various strategies have been applied to enhance the performance of catalysts including tuning the electronic structure,binding strength,coordination configuration as well as the introduction of multiple active sites and defects.In this review,the recent progress of Fe-based electrocatalysts and their coordination effect,syner gistic effect and def ect effect for nitrogen reduction reaction have been summarized.Our critical review focuses on the discussion of theoretical advancement,the performance origin of ENRR activity and selectivity of Fe-based electrocatalysts.

Theoretical investigation of CoTa_(2)0_(6)/graphene heterojunctions for oxygen evolution reaction

Water electrolysis is to split water into hydrogen and oxygen using electricity as the driving force.To obtain low-cost hydrogen in a large scale,it is critical to develop electrocatalysts based on earth abundant elements with a high efficiency.This computational work started with Cobalt on CoTh_(2)C)_(6)surface as the active site,CoTa_(2)O_(6)/Graphene heterojunctions have been explored as potential oxygen evolution reaction(OER)catalysts through density functional theory(DFT).We demonstrated that the electron transfer(_(6))from CoTa_(2)C)_(6)to graphene substrate can be utilized to boost the reactivity of Co-site,leading to an OER overpotential as low as 0.30 V when N-doped graphene is employed.Our findings offer novel design of heterojunctions as high performance OER catalysts.

Catalytic reduction of carbon dioxide over two-dimensional boron monolayer

Carbon dioxide reduction(CRR)is an attractive strategy for alleviating global warming and producing valuable fuels.In this work,we study the catalytic conversion of CO_(2)to C__(1)-C_(3) products on boron nanosheet in the presence of compressive strain by using density functional theory.Thermodynamic and microkinetic models are applied to demonstrate the favorable products,critical steps,and hydrogenation mechanisms.As demonstrated,the strain can turn metallic two-dimensional boron nanosheet to semiconductor,not only making boron sheets possess photo(electro)catalytic activity,but also improving energy efficiency and selectivity performance against hydrogen evolution reaction.By introducing the aqueous electrolytes,the hydrated alkali cations not only effect on the CO_(2) concentration,but also produce a bigger surface charge density and stronger interfacial electric filed.Especially,the selectivity of C_(2+) products is enhanced with the increase of alkali cations size by decreasing the kinetic barrier for CO dimerization and stabilizing the intermediates.The results highlight the significance of metal-free catalysts for CRR by the photoelectrochemical method and provide novel avenues for the development of new solar-energy utilization catalysts.