Carbon dioxide adsorption and conversion to methane and ethane on hydrogen boride sheets

Abstract

AbstractHydrogen boride (HB) sheets are metal-free two-dimensional materials comprising boron and hydrogen in a 1:1 stoichiometric ratio. In spite of the several advancements, the fundamental interactions between HB sheets and discrete molecules remain unclear. Here, we report the adsorption of CO2and its conversion to CH4and C2H6using hydrogen-deficient HB sheets. Although fresh HB sheets did not adsorb CO2, hydrogen-deficient HB sheets reproducibly physisorbed CO2at 297 K. The adsorption followed the Langmuir model with a saturation coverage of 2.4 × 10−4mol g−1and a heat of adsorption of approximately 20 kJ mol−1, which was supported by density functional theory calculations. When heated in a CO2atmosphere, hydrogen-deficient HB began reacting with CO2at 423 K. The detection of CH4and C2H6as CO2reaction products in a moist atmosphere indicated that hydrogen-deficient HB promotes C–C coupling and CO2conversion reactions. Our findings highlight the application potential of HB sheets as catalysts for CO2conversion.