Directional Regulation of Biomass Pyrolysis Gas Coupling for Hydrogen-Rich Fuel Gas Production over a Hydrophobic NiCo-CeO2/F-Ti3C2 Catalyst

Abstract

A key challenge in hydrogen-rich fuel gas production via biomass pyrolysis gas coupling is catalyst hydrothermal deactivation. In this study, hydrophobic F-Ti3C2 MXene nanosheets are prepared by a combination of HF-HCl etching and perfluorooctanesulfonic acid (PFOS) modification. Using the nanosheets as the support, CeO2 promoters and Ni-Co alloy active components are loaded via impregnation, nitrogen calcination and hydrogen reduction processes. Finally, a catalyst with high activity and high hydrophobicity is successfully prepared. The performance of the catalyst is tested in a fixed-bed reactor. The effects of total NiCo loading, Ni/Co molar ratio, and Ce loading on CO/CH4 conversion and H2 selectivity are systematically investigated. The catalyst is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle measurements, and the mechanisms underlying its activity and hydrophobicity enhancement are analyzed. The results are as follows: (1) The catalyst with a total NiCo loading of 13% (Ni/Co molar ratio of 3:1) and a Ce loading of 5% exhibits the optimal performance. (2) The optimal catalyst has a complete two-dimensional layered structure, with uniformly dispersed active species and a contact angle of 129.81°. (3) At the initial stage of the reaction, the CO conversion rate is 96.16%, the CH4 conversion rate is 60.16%, and the H2 selectivity is 97.87%, enabling efficient hydrogen production from biomass pyrolysis gas.