Liu Chuncheng, Uslamin Evgeny A, Khramenkova Elena, Sireci Enrico, Ouwehand Lucas T L J, Ganapathy Swapna, Kapteijn Freek, Pidko Evgeny A
Inorganic Systems Engineering, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands.
Catalysis Engineering, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands.
ACS Catal. 2022 Mar 4;12(5):3189-3200. doi: 10.1021/acscatal.1c05481. Epub 2022 Feb 23.
The production of valuable aromatics and the rapid catalyst deactivation due to coking are intimately related in the zeolite-catalyzed aromatization reactions. Here, we demonstrate that these two processes can be decoupled by promoting the Ga/HZSM-5 aromatization catalyst with Ca. The resulting bimetallic catalysts combine high selectivity to light aromatics with extended catalyst lifetime in the methanol-to-aromatics process. Evaluation of the catalytic performance combined with detailed catalyst characterization suggests that the added Ca interacts with the Ga-LAS, with a strong effect on the aromatization processes. A genetic algorithm approach complemented by ab initio thermodynamic analysis is used to elucidate the possible structures of bimetallic extraframework species formed under reaction conditions. The promotion effect of minute amounts of Ca is attributed to the stabilization of the intra-zeolite extraframework gallium oxide clusters with moderated dehydrogenation activity.
在沸石催化的芳构化反应中，有价值芳烃的生成与因结焦导致的催化剂快速失活密切相关。在此，我们证明通过用Ca促进Ga/HZSM - 5芳构化催化剂，这两个过程可以解耦。所得的双金属催化剂在甲醇制芳烃过程中结合了对轻质芳烃的高选择性和延长的催化剂寿命。催化性能评估与详细的催化剂表征相结合表明，添加的Ca与Ga - LAS相互作用，对芳构化过程有强烈影响。采用遗传算法方法并辅以从头算热力学分析来阐明反应条件下形成的双金属骨架外物种的可能结构。微量Ca的促进作用归因于具有适度脱氢活性的沸石内骨架外氧化镓簇的稳定化。
