Electronic state regulation induced by the strong metal–support interactions boosts the performance of alcohol oxidation reactions

Abstract

The strong metal–support interactions (SMSI) between metal and its support have been regarded as a valid approach to enhance the catalytic performance; however, the extent to which exploration of electronic state regulation affects catalytic performance of alcohol oxidation reactions (AOR) has been rarely reported. In this paper, PdAg nanoparticles loaded on a N-doped carbon substrate with controlled nitrogen content (PdAg@N_xC, x representing the nitrogen contents) was synthesized through a seeded synthesis strategy for alkaline AOR. Results show that the electronic state of PdAg nanoparticles was significantly modified after nitrogen doping in the carbon support. Experimental and theoretical results indicate that with increasing nitrogen content, the degree of electronic state regulation becomes increasingly significant. Density functional theory (DFT) calculations suggest that the increased degree of SMSI promotes OH* adsorption on the PdAg surface and weakens the binding between catalyst and CO*. As a result, the PdAg@N_15.3C with the highest N content exhibits excellent AOR performance, achieving a MA/SA of 10.8 A mg_Pd⁻¹/13.2 mA cm⁻² and 3.8 A mg_Pd⁻¹/4.7 mA cm⁻² on the EOR and MOR, respectively. Moreover, due to the changes in the adsorption energy of key intermediates on PdAg nanoparticles, the onset oxidation potential of PdAg@N_15.3C shows a negative shift of 180 mV compared to PdAg@C as revealed by CO stripping analysis, signifying an increase in the CO tolerance. Our study demonstrates the influence of the SMSI effect between the active center and the support on the catalytic performance for AOR and presents a pathway to achieve high AOR performance through SMSI engineering.