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    光辅助热催化驱动Ni−HAP低温高效催化甲烷干重整

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

    • 摘要: 甲烷干重整(Dry Reforming of Methane,DRM)反应能够将CH4和CO2 2种温室气体转化为合成气,兼具碳资源循环与高价值化工原料生产的双重优势,是推动实现碳达峰碳中和目标下能源催化转化的重要技术路径。然而,该反应耗能较高,需要在高温下进行。因此,开发低温、低能耗的DRM工艺是其迈向大规模工业化应用的关键。采用光辅助热催化策略,在模拟太阳光照的辅助下,在低温条件下大幅提高了DRM的反应效率与合成气产率,从而有效降低了能耗并提升了产能。结果表明:使用溶胶凝胶法制备的催化剂Ni−HAP,在H2氛围400 ℃还原后,拥有最佳DRM催化性能。通过原位X射线光电子能谱技术(ISI-XPS)、原位CH4程序升温脱附(CH4-TPD)、漫反射红外傅里叶变换光谱(DRIFTS)表征,并结合理论计算,探究了低温热催化下光催化的引入对DRM反应的促进机制。结果表明:在热催化基础下,光催化帮助催化剂表面形成了更高强度的CH4吸附位点,促进更好地吸附裂解CH4,降低了反应活化能。基于变温组试验和变光照强度组试验,Ni−HAP催化剂在光辅助热催化下DRM产率达到纯热催化的1.8倍,最高合成气产率为346.71 mmol/(g·h),具有出色的光利用率。通过结合传统热催化与光催化的优势,显著降低了DRM反应温度,推进反应进行,为发展低温催化DRM技术提供了新思路。

       

      Abstract: 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.

       

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