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

Hydrogen 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 CO(2) and its conversion to CH(4) and C(2)H(6) using hydrogen-deficient HB sheets. Although fresh HB sheets did not adsorb CO(2), hydrogen-deficient HB sheets reproducibly physisorbed CO(2) at 297 K. The adsorption followed the Langmuir model with a saturation coverage of 2.4 × 10(−4) mol g(−1) and a heat of adsorption of approximately 20 kJ mol(−1), which was supported by density functional theory calculations. When heated in a CO(2) atmosphere, hydrogen-deficient HB began reacting with CO(2) at 423 K. The detection of CH(4) and C(2)H(6) as CO(2) reaction products in a moist atmosphere indicated that hydrogen-deficient HB promotes C–C coupling and CO(2) conversion reactions. Our findings highlight the application potential of HB sheets as catalysts for CO(2) conversion.