Atomic Dispersed Hetero‑Pairs for Enhanced Electrocatalytic CO_(2)Reduction

Electrochemical carbon dioxide reduction reaction(CO_(2)RR)involves a variety of intermediates with highly correlated reaction and ad-desorption energies,hindering optimization of the catalytic activity.For example,increasing the binding of the*COOH to the active site will generally increase the*CO desorption energy.Breaking this relationship may be expected to dramatically improve the intrinsic activity of CO_(2)RR,but remains an unsolved challenge.Herein,we addressed this conundrum by constructing a unique atomic dispersed hetero-pair consisting of Mo-Fe di-atoms anchored on N-doped carbon carrier.This system shows an unprecedented CO_(2)RR intrinsic activity with TOF of 3336 h−1,high selectivity toward CO production,Faradaic efficiency of 95.96%at−0.60 V and excellent stability.Theoretical calculations show that the Mo-Fe diatomic sites increased the*COOH intermediate adsorption energy by bridging adsorption of*COOH intermediates.At the same time,d-d orbital coupling in the Mo-Fe di-atom results in electron delocalization and facilitates desorption of*CO intermediates.Thus,the undesirable correlation between these steps is broken.This work provides a promising approach,specifically the use of di-atoms,for breaking unfavorable relationships based on understanding of the catalytic mechanisms at the atomic scale.

Recent advances of MXene as promising catalysts for electrochemical nitrogen reduction reaction

Electrochemical reduction of N2,as an eco-friendly alternative,not only allows the use of protons in water as a source of hydrogen under mild conditions but also can be driven by renewable electric energy.The major challenge is to identify high-efficiency electrocatalysts.MXene is a new class of 2D transition metal carbides,nitrides,and carbonitrides that have received significant attention in electrocatalysis.The investigations on MXene in electrocatalytic nitrogen fixation are rapidly proceeding,and some breakthroughs have emerged ve ry recently due to MXenes’satisfacto ry catalytic activity.Here,the recent progress concerning the MXene-based catalysts for electrochemical N2 reduction reaction(NRR)is highlighted.In regards to giving guidelines for exploring more efficient MXene-based catalysts for the NRR,the fabrication and surface modification of MXene are discussed.Besides,the shortcomings and challenges of current research are summarized and the future research directions are prospected.

Sulfur defect-rich WS nanosheet electrocatalysts for N reduction

Seeking catalysts with high electrocatalytic activity for ambient-condition N2 reduction reaction (NRR) remains an ongoing challenge due to the chemical inertness of N2.Herein,defect-rich WS2 nanosheets (WS2-x) were designed as an efficient electrocatalyst for NRR,which were prepared via vulcanizing the oxygen-vacancy-rich tungsten oxide in a vacuum tube.The sulfur defects were conducive to the adsorption and activation of N2.In neutral electrolyte of 0.1 mol L^(-1)Na2SO_(4) at-0.60 V vs.reversible hydrogen electrode,such WS2-xoffered a high Faradaic efficiency of 12.1%with a NH3generation rate of 16.38μg h-1mg-1cat..