CuCo纳米片高效电催化还原硝酸盐产氨

CuCo Nanosheet for Efficient Electrochemical Reduction of Nitrate to Ammonia

从废水处理和低碳环保的角度出发,开发高效还原硝态氮(NO^(-)_(3))为氨(NH_(3))的电催化剂越来越受到人们的关注。在此,我们提出了一种生态友好,经济高效,生物仿生的Cu_(50)Co_(50)纳米片电催化剂,用于电化学还原NO^(-)_(3)到NH_(3)(NO^(-)_(3)RR),作为Haber-Bosch法生产氨过程的一个有前景的替代途径。Cu_(50)Co_(50)纳米片在-0.2 V vs.RHE的条件下产生NH_(3)的法拉第效率为100%±1%,电流密度为1035 mA·cm^(-2),对应的NH_(3)生产速率达到4.8 mmol·cm^(-2)·h-1(960 mmol·g^(-1)·h^(-1))。通过电化学原位红外光谱(FTIR)和原位壳层隔离纳米颗粒增强拉曼光谱(SHINERS)对NO^(-)_(3)RR过程中的中间物种进行检测,结合电化学测试,分析了其还原机理,并利用DFT计算对各反应步骤进行了验证。实验结果显示,铜(Cu)和钴(Co)之间有很强的协同作用,Co位点通过*H物种促进NO^(-)_(3)及其中间体加氢生成NH_(3)。

The development of capable electrocatalysts for efficient reduction of nitrate(NO^(-)_(3))to ammonia(NH_(3))is drawing increasing interest for the sake of wastewater recycling.Herein we present an eco-friendly,cost effective,bio-inspired Cu_(50)Co_(50)nanosheet electrocatalyst for electrochemical reduction of NO^(-)_(3)to NH_(3)(NO^(-)_(3)RR)as a promising alternative route to the Haber-Bosch method and the biological NO^(-)_(3)reductase processes.The Cu_(50)Co_(50)nanosheet with a low overpotentialη@10mA·cm^(-2)of 498mV delivers a 100%±1%Faradaic efficiency at an ampere-level current density of 1035mA·cm^(-2)for NH_(3)production at-0.2Vvs.RHE.The NH_(3)production rate reaches 4.8mmol·cm^(-2)·h-1(960mmol·g^(-1)·h^(-1)).A mechanistic study was conducted using electrochemical in-situ FTIR spectroscopy,in-situ shell-isolated nanoparticle enhanced Raman spectroscopy and DFT calculations to identify different steps during the NO^(-)_(3)RR.The experimental data revealed a strong synergy between copper(Cu)and cobalt(Co),with Co sites promoting the hydrogenation of NO^(-)_(3)and its intermediates to NH_(3)via adsorbed*H species.