摘要
电化学硝酸根还原制氨(NRA)可以同时实现硝酸盐废水处理和氨合成,是一种很有前途的环保节能策略.目前构建高效的电催化剂是人们关注的焦点.本文构建了TiO_(2)@C/Fe_(2)O_(3)纳米片阵列作为高效催化剂,采用多种表征手段系统研究了水热碳的引入对NRA性能的影响.我们发现水热碳既可作为良导体实现电荷的快速传递,又可作为还原剂引入更多的氧空位,实现了“一石二鸟”催化剂构建策略.与TiO_(2)/Fe_(2)O_(3)相比,TiO_(2)@C/Fe_(2)O_(3)具有更高的NRA性能,硝酸盐转化率为88.6%、氨选择性为83.4%、法拉第效率为85.3%、氨收率为0.2176 mmol h^(-1)cm^(-2).此外,在9次循环实验后,TiO_(2)@C/Fe_(2)O_(3)的高活性仍得以保持,证实了TiO_(2)@C/Fe_(2)O_(3)出色的稳定性.此外,我们利用电化学准原位电子自旋共振实验、电化学原位衰减全反射傅立叶变换红外测量和在线差分电化学质谱法推导了可能的NRA反应途径.这种引入水热碳中间层的策略可为开发新型NRA电催化剂开辟新的途径.
Electrochemical nitrate reduction to ammonia(NRA)is considered a promising strategy for environmental protection and energy saving because it can simultaneously achieve nitrate wastewater treatment and ammonia synthesis.However,currently,this method suffers from the lack of ef-ficient electrocatalysts.In this work,through a“killing two birds with one stone”strategy,a catalyst,TiO_(2)@C/Fe_(2)O_(3)na-nosheet arrays(NSAs),was fabricated by introducing hydro-thermal carbon(HTC),which not only accelerates the charge transfer due to its good conductivity but also provides abun-dant oxygen vacancies owing to its nice reducibility,finally improving the NRA performance.Compared with TiO_(2)/Fe_(2)O_(3)NSAs,TiO_(2)@C/Fe_(2)O_(3)exhibited higher NRA performance with a nitrate conversion of 88.6%,ammonia selectivity of 83.4%,Faradaic efficiency of 85.3%,and ammonia yield of 0.2176 mmol h^(−1)cm^(−2).Moreover,the retention of high activ-ity in nine cyclic experiments confirmed the outstanding sta-bility of TiO_(2)@C/Fe_(2)O_(3).Furthermore,the possible NRA reaction pathway was derived from the results of electro-chemical quasi in situ electron spin resonance experiments,electrochemical in situ attenuated total reflection Fourier transform infrared measurement and online differential electrochemical mass spectrometry.This feasible strategy of introducing an HTC interlayer may open new avenues for developing novel NRA electrocatalysts.
作者
吴璇
马爱静
刘丹
李雪倩
周颖康
Alex T.Kuvarega
Bhekie B.Mamba
李虎
桂建舟
Xuan Wu;Aijing Ma;Dan Liu;Xueqian Li;Yingkang Zhou;Alex T.Kuvarega;Bhekie B.Mamba;Hu Li;Jianzhou Gui(State Key Laboratory of Separation Membranes and Membrane Processes,School of Material Science and Technology,Tiangong University,Tianjin 300387,China;Tianjin Key Laboratory of Green Chemical Technology and Process Engineering,School of Chemical Engineering and Technology,Tiangong University,Tianjin 300387,China;School of Chemistry,Tiangong University,Tianjin 300387,China;Institute for Nanotechnology and Water Sustainability,College of Science,Engineering and Technology,University of South Africa,Florida 1709,Johannesburg,South Africa;Ningxia Coal Industry Co.,Ltd.,CHN ENERGY,Yinchuan 750011,China)
基金
financially supported by the National Natural Science Foundation of China(21576211)
Tianjin Science and Technology Program(22ZYJDSS00060 and 22YDTPJC00920)
the Program for Tianjin Innovative Research Team in Universities(TD13-5031)
Tianjin 131 Research Team of Innovative Talents。
