CuNi双金属MOFs串联催化促进硝酸盐还原合成氨OA

Electrocatalytic nitrate reduction reaction(NO3RR),as a green technology for producing ammonia and purifying wastewater,faces challenges in terms of nitrite intermediate accumulation and competitive hydrogen evolution reactions.Tandem catalytic strategy(NO3-→NO2-→NH3)is expected to significantly improve the rate and selectivity of ammonia production.Therefore,designing and constructing dual active sites with different catalytic properties contributes to improving reaction activity.Herein,a CuNi bimetallic metal organic framework(MOF)tandem catalytic system using well-defined MOFs as templates was constructed through simple hydrothermal synthesis.The research results indicated that Cu active sites could efficiently catalyze the reduction of NO3-to NO2-,while Ni sites exhibited excellent active hydrogen species *H supply capacity and NO2-conversion efficiency,forming an efficient tandem catalytic mechanism with Cu sites,and achieving a Faraday efficiency of up to 90.1%for ammonia synthesis and an ammonia yield of 28.8 mg·h-1·mgcat-1.In addition,the bimetallic MOFs catalyst showed excellent cycling stability without any degradation in ammonia synthesis after multiple cycling tests.This work provides new insights for the design and optimization of high-performance tandem catalysts.