Promoting nitric oxide electroreduction to ammonia over electron-rich Cu modulated by Ru doping

Electrocatalytic nitric oxide(NO)reduction is a promising strategy to produce ammonia.Developing a facile approach to synthesize efficient catalysts with enhanced NO electroreduction performance is highly desirable.Here,a series of Ru-doped Cu materials are constructed through in situ electroreduction of corresponding metal hydroxides.The optimized Ru_(0.05)Cu_(0.95)exhibits superior electrocatalytic performance for ammonia synthesis by using NO/Ar(1/4,n/n)as the feedstocks(Faradaic efficiency:64.9%,yield rate:17.68μmol cm^(-2)h^(-1)),obviously outperforming Cu counterpart(Faradaic efficiency:33.0%,yield rate:5.73μmol cm^(-2)h^(-1)).Electrochemical in situ Fourier transform infrared(FTIR)spectroscopy and online differential electrochemical mass spectrometry(DEMS)are adopted to detect intermediates and unveil the possible reaction pathway.The downshift of the Cu d-band center induced by Ru doping facilitates the rate-limiting hydrogenation step and decreases the desorption energy of NH_(3),leading to high Faradaic efficiency and yield of ammonia.