One-Pot synthesis of Ni-B2O3/Al2O3 catalysts with high resistance to coke formation for the dry reforming reaction of methane

The production of hydrogen from dry reforming of methane (DRM) is crucial for the energy transition, aiming for a more sustainable energy matrix due to its similarity to biogas reforming, which provides a renewable substrate for large-scale synthesis gas production. In this context, the efficiency of catalysts plays a fundamental role in optimizing this process, considering the extreme operational conditions in terms of temperature and competing reactions. This study investigates the synthesis, characterization, and stability of nickel catalysts supported on alumina, using a one-pot synthetic approach via microwave-assisted combustion, compared to catalysts synthesized by the commonly used wet impregnation method. Structural characterization was performed using Xray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and temperature-programmed reduction (TPR-H2). Textural properties were assessed through nitrogen (N2) adsorption. The results showed that the catalysts synthesized by the one-pot method tend to have a high dispersion of nickel particles and a larger surface area, contributing to superior catalytic activity. Catalytic stability tests revealed that the catalysts promoted with B2O3 exhibited lower deactivation and reduced coke formation compared to unpromoted catalysts; however, an increase in the amount of B2O3 raised deactivation due to sintering, which was mitigated by the one-pot method that enhances metal-support interaction. The one-pot synthetized nickel catalyst with 2.5 wt% stood out, with stability more than ten times greater than that of the conventional Ni/Al2O3 catalyst and four times greater than the promoted catalyst synthesized via impregnation. Among the 3 catalysts mentioned, the final CH4 conversions were 78 %, 72 %, and 75 %, respectively, while the H2 yields were 60 %, 55 %, and 58 % after 12 h of reaction. The findings indicate that promotion with B2O3 and the one-pot synthesis significantly improved the stability and efficiency of the catalysts, offering potential for larger-scale synthesis gas production applications.