Cunha Adelino F, Morales-Torres Sergio, Pastrana-Martínez Luisa M, Martins António A, Mata Teresa M, Caetano Nídia S, Loureiro José M
Laboratory of Separation and Reaction Engineering, Associate Laboratory LSRE-LCM, Department of Chemical Engineering, Faculty of Engineering, University of Porto Rua Dr. Roberto Frias 4200-465 Porto Portugal.
School of Engineering (ISEP), Polytechnic of Porto (P.Porto) R. Dr. António Bernardino de Almeida 431 4249-015 Porto Portugal
RSC Adv. 2020 Jun 3;10(36):21158-21173. doi: 10.1039/d0ra03264f. eCollection 2020 Jun 2.
Steam reforming of methane (SRM) and dry reforming of methane (DRM) are frequently used in the production of syngas; however, the bi-reforming of methane (BRM) is an interesting and alternative process. In this study, BRM was studied over MgO, a layered double hydroxide (LDH) phase that was destroyed between 600 °C and 900 °C during the reaction. It showed good sorption capacity for CO at relatively low temperatures (<500 °C), with CO adsorption being a pre-requisite for its catalytic conversion. Among the tested materials, the potassium-promoted LDH showed the highest activity, achieving a maximum CO conversion of 75%. The results suggest that at high temperature, the electronic structure of the used materials influences the destabilization of the feed in the order of methane, water and carbon dioxide. K promotes the catalytic activity, compensates the presence of large Ni particle sizes originating from the high metal loading, and favors the formation of Mg-Al-spinel. K is known to be an electronic promoter that releases electrons, which flow to the active metal. This electron flow induces instability on the molecule to be converted, and most probably, also induces size variations on the respective active nickel metal. The influence of the operating conditions in the range of 300 °C to 900 °C on the conversion of the reactants and product distribution was studied. Accordingly, it was concluded that it is only possible to obtain molar ratios of hydrogen-to-carbon monoxide close to two at high temperatures, a pre-requisite for the synthesis of methanol.
甲烷蒸汽重整（SRM）和甲烷干重整（DRM）常用于合成气的生产；然而，甲烷双重整（BRM）是一个有趣的替代工艺。在本研究中，对BRM在MgO上进行了研究，MgO是一种层状双氢氧化物（LDH）相，在反应过程中于600℃至900℃之间被破坏。它在相对较低的温度（<500℃）下对CO表现出良好的吸附能力，CO吸附是其催化转化的先决条件。在所测试的材料中，钾促进的LDH表现出最高的活性，最大CO转化率达到75%。结果表明，在高温下，所用材料的电子结构按甲烷、水和二氧化碳的顺序影响原料的去稳定化。K促进催化活性，补偿因高金属负载而产生的大尺寸Ni颗粒的存在，并有利于Mg-Al-尖晶石的形成。已知K是一种释放电子的电子促进剂，电子流向活性金属。这种电子流会导致待转化分子的不稳定，很可能还会导致相应活性镍金属的尺寸变化。研究了300℃至900℃范围内操作条件对反应物转化率和产物分布的影响。因此，得出结论，只有在高温下才有可能获得接近2的氢与一氧化碳的摩尔比，这是甲醇合成的先决条件。
