Abstract Glycerol dehydration to value-added acrolein over zeolite catalysts is a useful approach to offer a sustainable economic route for the biodiesel industry. Glycerol dehydration over H-ZSM-5 with conventional morphology often exhibits a significant mass transfer limitation and inhibits the access to active sites in the micropores, which causes low activity, selectivity, and severe catalyst deactivation. In this study, a significant impact of b-axis channel length on acrolein selectivity and catalyst activity was revealed by using H-ZSM-5 synthesized with varied channel length in b-axis of 60, 130, 180, and 250 nm. Complete glycerol conversion and high acrolein selectivity (88%) were observed over H-ZSM-5 with 60 nm channels length in b-axis, due to high availability of active sites and enhanced diffusion through the shortest channels, which dramatically suppressed the coke formation. The catalysts with long b-axis channels exhibited a slow internal diffusion, leading to increased polymerization side reactions and coke formation.

中文翻译：

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通过调节甘油脱水生成丙烯醛的 b 轴通道长度来控制 H-ZSM-5 的选择性和失活

摘要 在沸石催化剂上将甘油脱水成高附加值的丙烯醛是一种有用的方法，可为生物柴油行业提供可持续的经济途径。具有常规形态的 H-ZSM-5 上的甘油脱水通常表现出显着的传质限制并抑制进入微孔中的活性位点，这导致低活性、选择性和严重的催化剂失活。在这项研究中，通过使用合成的 H-ZSM-5，在 b 轴上的不同通道长度为 60、130、180 和 250 nm，揭示了 b 轴通道长度对丙烯醛选择性和催化剂活性的显着影响。由于活性位点的高可用性和通过最短通道的增强扩散，在 H-ZSM-5 上观察到完全甘油转化和高丙烯醛选择性 (88%)，b 轴通道长度为 60 nm，这极大地抑制了焦炭的形成。具有长 b 轴通道的催化剂表现出缓慢的内部扩散，导致聚合副反应和焦炭形成增加。