美国密西根大学Suljo Linic报道了通过协同设计催化剂-膜系统克服丙烷脱氢的局限性。相关研究成果发表在2024年3月22日出版的《科学》。

通过丙烷脱氢（PDH）生产丙烯是吸热的，实现可接受的丙烷转化所需的高温，导致传统催化剂的低选择性和严重的碳诱导失活。

研究人员开发了一种催化剂膜系统，可以去除氢气副产物，从而实现超过平衡极限的丙烷转化率。在该共同设计的系统中，二氧化硅/氧化铝（SiO₂/Al₂O₃）中空纤维氢膜在管侧填充有选择性铂锡（Pt₁Sn₁/SiO₂）PDH催化剂，氢从管扩散到壳侧。

研究人员证明，催化剂膜系统可以实现丙烷转化率>140%的标称平衡转化率，丙烯选择性>98%，而不会使系统组分失活。研究还表明，通过在催化剂膜系统的壳侧引入氧气，可以将管侧的吸热PDH反应与壳侧的放热氢氧化耦合起来。这种耦合导致更高的氢传输速率，导致丙烷转化率的进一步提高以及所需的热中性系统运行。

附：英文原文

Title: Overcoming limitations in propanedehydrogenation by codesigning catalyst-membrane systems

Author: Rawan Almallahi, James Wortman, Suljo Linic

Issue&Volume: 2024-03-22

Abstract: Propylene production through propane dehydrogenation (PDH) is endothermic, and high temperatures required to achieve acceptable propane conversions lead to low selectivity and severe carbon-induced deactivation of conventional catalysts. We developed a catalyst-membrane system that removes the hydrogen by-product and can thus achieve propane conversions that exceed equilibrium limits. In this codesigned system, a silica/alumina (SiO2/Al2O3) hollow-fiber hydrogen membrane was packed with a selective platinum-tin (Pt1Sn1/SiO2) PDH catalyst on the tube side with hydrogen diffusing from the tube to the shell side. We demonstrate that the catalyst-membrane system can achieve propane conversions >140% of the nominal equilibrium conversion with a propylene selectivity >98% without deactivation of the system components. We also show that by introducing oxygen on the shell side of the catalyst-membrane system, we can couple the endothermic PDH reaction on the tube side with exothermic hydrogen oxidation on the shell side. This coupling results in higher rates of hydrogen transport, leading to further enhancements in the propane conversion as well as desired thermoneutral system operation.

DOI: adh3712

Source: https://www.science.org/doi/10.1126/science.adh3712