Morales Miguel, Laguna-Bercero Miguel Ángel, Jiménez-Piqué Emilio
CIEFMA-Department of Materials Science and Engineering, EEBE-Campus Diagonal Besòs, Universitat Politècnica de Catalunya-BarcelonaTech, C/Eduard Maristany 16, 08019 Barcelona, Spain.
Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, C/Eduard Maristany 16, 08019 Barcelona, Spain.
ACS Appl Energy Mater. 2023 Jul 25;6(15):7887-7898. doi: 10.1021/acsaem.3c00778. eCollection 2023 Aug 14.
LaSrCoO (LSC) perovskite, as a potential catalyst precursor for hydrogen (H)-rich production by steam reforming of methanol (SRM) and oxidative steam reforming of methanol (OSRM), was investigated. For this purpose, LSC was synthesized by the citrate sol-gel method and characterized by complementary analytical techniques. The catalytic activity was studied for the as-prepared and prereduced LSC and compared with the undoped LaCoO (LCO) at several feed gas compositions. Furthermore, the degradation and regeneration of LSC under repeated redox cycles were studied. The results evidenced that the increase in the water/methanol ratio under SRM, and the O addition under OSRM, increased the CO formation and decreased both the H selectivity and catalyst deactivation caused by carbon deposition. Methanol conversion of the prereduced LSC was significantly enhanced at a lower temperature than that of as-prepared LSC and undoped LCO. This was attributed to the performance of metallic cobalt nanoparticles highly dispersed under reducing atmospheres. The reoxidation program in repetitive redox cycles played a crucial role in the regeneration of catalysts, which could be regenerated to the initial perovskite structure under a specific thermal treatment, minimizing the degradation of the catalytic activity and surface.
作为甲醇蒸汽重整(SRM)和甲醇氧化蒸汽重整(OSRM)制富氢产物的潜在催化剂前驱体,对LaSrCoO(LSC)钙钛矿进行了研究。为此,采用柠檬酸盐溶胶 - 凝胶法合成了LSC,并通过多种分析技术对其进行了表征。研究了所制备的和预还原的LSC在几种原料气组成下的催化活性,并与未掺杂的LaCoO(LCO)进行了比较。此外,还研究了LSC在反复氧化还原循环下的降解和再生情况。结果表明,SRM条件下水/甲醇比的增加以及OSRM条件下氧的添加,增加了CO的生成,同时降低了H的选择性以及由积碳导致的催化剂失活。预还原的LSC在比制备态LSC和未掺杂LCO更低的温度下甲醇转化率显著提高。这归因于在还原气氛下高度分散的金属钴纳米颗粒的性能。重复氧化还原循环中的再氧化程序在催化剂再生中起着关键作用,通过特定的热处理可以将其再生为初始的钙钛矿结构,使催化活性和表面的降解最小化。