Room-temperature hydrogen spillover achieving stoichiometric hydrogenation of NO₃⁻ and NO₂⁻ into N₂ over CuPd nanowire network

The development of an efficient hydrogen spillover (HS) catalyst achieves the stoichiometric chemoselective hydrogenation of NO₃⁻ and NO₂⁻ into N₂ at room temperature, which is extremely challenging. Herein, we report a Cu_xPd_1−x nanowire network (NWN) (x = 7, 5, or 3) with tunable hydrogen spillover rate of formic acid (FA) with polyvinylpyrrolidine imine (PVPI) modifying its surface. The presence of PVPI boosts the catalytic selectivity and activity of CuPd NWN for FA dehydrogenation and, more importantly, serves as a modem to tune the HS rate of FA and to stoichiometrically hydrogenate NO₃⁻ and NO₂⁻ to N₂ at room temperature. The density functional theory (DFT) reveals that the CuPd (130 h⁻¹) has a weaker HS rate than AgPd (390 h⁻¹), but the CuPd (> 99%) has a higher utilization of HS than AgPd (31%). Our studies demonstrate a new approach of tuning the FA HS rate and maximizing the application for stoichiometric chemoselective hydrogenation reaction, which will be important for hydrogen generation and its applications.