Surface basic site effect on CoLa/m-Al2O3 catalysts for dry reforming of methane

• Published in: Molecular catalysis Vol. 562; p. 114205
• Main Authors: Liu, Yanni, Cai, Yajing, Liang, Zhoujie, Zhang, Guojie, Liu, Jun, Zhang, Yunfei, Li, Tianshan, Zhang, Xiaodi, Wang, Ying, Zhao, Yuqiong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2024
• Subjects: Alkali earth metal; Basic sites; Co-based; Dry reforming of methane; Support; Alkali earth metal; Support; Dry reforming of methane; Co-based; Basic sites
• ISSN: 2468-8231; 2468-8231
• DOI: 10.1016/j.mcat.2024.114205

•Effect of support surface basic sites modulation on catalysts performance was investigated.•CoLa/MgMA catalysts exhibited a good anti-sintering and anti-carbon properties.•The reaction kinetics of different alkali metal- modulated catalysts were studied.•Mg and Ca modified provide more surface basic sites to facilitate CO2 adsorption and activation.•The introduction of Mg and Ca promotes Co dispersion. Dry reforming of methane (DRM) is a novel technology that enables the direct utilization of greenhouse gases (CH4 and CO2) for the production of value-added products. In the DRM reaction, the acid-base characteristics of the catalyst support play a pivotal role in determining the performance of the catalyst. In this study, a series of Co-based catalysts with different alkali earth metal-modified Al2O3 composite supports, specifically m-Al2O3 (m=Ca, Mg, and Ba), were prepared using the impregnation method. Various characterization techniques were employed to investigate the impact of alkaline site modulation on the support surface with respect to anti-sintering and anti-coking properties. The results demonstrate that the m-Al2O3 composite support catalysts, prepared with Mg and Ca modulation, exhibit an abundance of basic sites and oxygen vacancies. This promotes the adsorption and activation of CO2, enhances the rate of carbon elimination, and effectively addresses carbon deposition and metal sintering issues. Notably, the CoLa/Mg-Al2O3 catalyst shows the highest performance under reaction conditions of 750 °C, with CH4 and CO2 conversions reaching 92.3 % and 97.5 %, respectively. On the other hand, the CoLa/Ba-Al2O3 catalysts display poor performance in dry reforming. Kinetic studies indicate that CoLa/Mg-Al2O3 catalyst significantly reduce the apparent activation energy required for CH4 and CO2 cracking. Furthermore, it is demonstrated that the introduction of alkali earth metals can promote the dissociation of CH4 and CO2. [Display omitted]