Light-assisted thermal catalysis driving low-temperature efficient dry reforming of methane over Ni−HAP catalyst

The Dry Reforming of Methane （DRM） reaction is capable of converting two greenhouse gases, CH₄ and CO₂, into syngas, which combines the advantages of carbon recycling and high-value chemical raw material production, and is an important technological pathway to promote the catalytic conversion of energy under the goal of carbon neutrality for carbon peaking. However, the reaction is energy-consuming and needs to be carried out at high temperatures. Therefore, the development of a low-temperature, low-energy DRM process is a central key to move it toward large-scale industrial applications. In this study, by introducing a light-assisted thermocatalytic strategy, the reaction efficiency and syngas yield of DRM were dramatically improved under low-temperature conditions with the assistance of simulated solar illumination, thus effectively reducing energy consumption and enhancing production capacity. The experimental results showed that the catalyst Ni−HAP prepared by sol-gel method possessed the best DRM catalytic performance after the reduction of H₂ atmosphere at 400 ℃. The promotion mechanism of the DRM reaction by the introduction of photocatalysis under low-temperature thermocatalysis was investigated by in-situ X-ray photoelectron spectroscopy （ISI-XPS）, in-situ CH₄ programmed temperature-raising desorption （CH₄-TPD）, and diffuse reflectance infrared fourier transform spectroscopy （DRIFTS） characterization, and combined with theoretical calculations. The results showed that the photocatalysis helped to form higher intensity CH₄ adsorption sites on the catalyst surface on the basis of thermal catalysis, which promoted better adsorption and cleavage of CH₄ and reduced the reaction activation energy. Based on the variable temperature group experiments and variable light intensity group experiments, the DRM yield of Ni−HAP catalyst under light-assisted thermocatalysis reached 1.8 times that of pure thermocatalysis, and the highest syngas yield was 346.71 mmol/（g·h）, which had an excellent photo-utilization rate. The present work combines the advantages of traditional thermal catalysis and photocatalysis, significantly reduces the DRM reaction temperature, advances the reaction, and provides a new idea for the development of low-temperature catalytic DRM technology.