Process optimization and kinetic study for solar-driven photocatalytic methane bi-reforming over TiO2/Ti3C2 supported CoAlLa-LDH-g-C3N4 dual S-scheme nanocomposite

Abstract

The bireforming of methane (CH4) with carbon dioxide (CO2) and water, called BRM, is a process for generating syngas, which is utilized as a feed for methanol production. The formation of multi-heterojunction by hybridizing cobalt aluminum lanthanum layered double hydroxide (CoAlLa-LDH), and TiO2Anatase/Rutile@Ti3C2 MXene (TiO2A/R@Ti3C2) with graphitic carbon nitride (g-C3N4) to form a g-C3N4/TiO2A/R@Ti3C2/CoAlLa-LDH dual-S-scheme composite performed as an excellent candidate for photocatalytic BRM. The photocatalytic performance was studied for CO2 dry reforming of methane (DRM), bireforming of methane (BRM), and CO2 reduction with H2O. The photocatalytic BRM was found to be an efficient reforming system with high-quality syngas production. The efficiency of the BRM process was then optimized by employing Response Surface Methodology (RSM). In RSM studies, it was inferred that in the photocatalytic BRM at the feed ratio of 1.67 for (CO2/CH4), the CO production reached a maximum with a value of 25.24 μmol at 4.68 h; however, increasing it further caused a decrease in CO production. Furthermore, at a feed ratio of 1.41 for CO2/CH4, the production of H2 reached its maximum with a value of 23.05 μmol at 4.93 h. The hydrogen-rich syngas production demonstrated excellent stability. The photocatalyst stability and regeneration characteristics were studied, demonstrating no decrease in the syngas production or quality.