Platinum Group Metal-Indium Carbon-Interstitial Compounds for Hydrogen Production

Abstract

Carbon-interstitial compounds of precious metal alloys (C_i-PMA) have attracted increased attention as effective catalytic materials, but their precise and controllable synthesis remains significant challenges. Herein, we have established a universal approach for the straightforward synthesis of supported C_i-platinum group metal-indium alloys (M₃InCx, M = Pt, Pd, Ni, x = 0.5 or 1). The control experiment results indicate that the C atoms in Pt₃InC_0.5 come from the solvent. Furthermore, 0.2 wt.% Pt₃InC_0.5/SiO₂ exhibits excellent catalytic performance for aqueous phase reforming (APR) of methanol (CH₃OH) to produce hydrogen, with productivity and turnover frequency of 310.0 ⁻¹mol·kgcat·h⁻¹ and 30 126 h⁻¹ at 200°C, which are 1.7 times greater than those of Pt₃In/SiO₂. The infrared results of CH₃OH adsorption reveal that the substantially better performance for APR of CH₃OH of Pt₃InC_0.5/SiO₂ than Pt₃In/SiO₂ is due to its significantly enhanced CH bond dissociation ability. This study not only provides a straightforward and universal approach for the controlled synthesis of C_i-PMA but also stimulates fundamental research into C_i-PMA for catalysis and other applications.