Hybrid Pd50-Ru50/MXene (Ti3C2Tx) nanocatalyst for effective hydrogenation of CO2 to methanol toward climate change control

Abstract

Increase in atmospheric carbon dioxide (CO2) concentration has motivated researchers to develop large-scale CO2 sequestration and subsequent fuel conversion processes using various nanocatalysts. Herein, a 2D alloyed Pd50-Ru50 nanoparticles decorated MXene (Pd50-Ru50/MXene) nanocatalyst for efficient hydrogenation of CO2 into selective production of methanol is successfully fabricated and analyzed for its performance. HR-TEM and BET studies showed that hexagonal close-packed Pd50-Ru50 was formed with an average size of 3.2 nm and grown on the MXene nanosheets resulting in a higher specific surface area of 120 m2 g−1. Among the various catalysts studied, Pd50-Ru50/MXene showed a superior catalytic activity for hydrogenation of CO2 into selective production of CH3OH. The CO2 hydrogenation process involved the hydrolysis of NaBH4 (H2 facilitator) with ethylene glycol as CO2 capture agent. The Pd50-Ru50/MXene catalyst produced a higher CO2 conversion efficiency of 78% with a CH3OH yield of 76% (total turnover number based on Pd50-Ru50 = 2932) under mild conditions (pCO2 = 10 bar; T = 150 °C; t = 12 h). The recyclability test and morphological analysis of the spent Pd50-Ru50/MXene catalyst demonstrated its chemical stability even after prolonged usage for several hours indicating its promise for commercial-scale CO2 capture and renewable liquid fuel production.