Sun Qingdi, Wang Ziyue, Liu Liyang, Tao Leiming, He Xiaohui, Ji Hongbing
Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, Fine Chemical Industry Research Institute, School of Chemistry, IGCME, Sun Yat-sen University, Guangzhou, 510275, P. R. China.
School of Chemical Engineering, Guangdong University of Petrochemical Technology, Maoming, 525000, P. R. China.
ChemSusChem. 2025 May 6:e2402759. doi: 10.1002/cssc.202402759.
Propane dehydrogenation (PDH), which produces propylene and by-produces hydrogen, attracts considerable attention in the chemical industry. Alkali metals, budget friendly and commonly used as additives to optimize the performance of Pt-based alloy catalysts, are extensively utilized in the PDH industry. Herein, the structure and catalytic performance of the commercial catalyst (PtK/θ-AlO) and contrast samples (PtK/θ-AlO-N and Pt/θ-AlO) are analyzed. According to the catalytic test, the PtK/θ-AlO exhibits better catalytic performance, which achieves >95% propylene selectivity and maintaining a high propane yield (>36%) during stability testing. Observations reveal that the initial propylene selectivity of the Pt-based catalysts is inversely correlated with the total acidity and strong acid site content. The introducing of K element significantly reduces the acidity of the catalyst and enhances the propylene selectivity. Moreover, the presence of Cl, co-introduced with K, improves the catalytic stability, while the slight increase in the acidity of catalysts decreases the propylene selectivity. The enrichment of the electron density of PtK nanoparticles contributes to the improvement of catalytic performance. Density functional theory calculations suggest that lower propylene adsorption energy and higher barrier for propylene deep dehydrogenation reaction on the PtK-(100) surface enhance the propylene selectivity of the PtK/θ-AlO catalyst.
丙烷脱氢（PDH）可生产丙烯并副产氢气，在化学工业中备受关注。碱金属价格低廉，常用作添加剂来优化铂基合金催化剂的性能，在PDH工业中得到广泛应用。在此，对商业催化剂（PtK/θ-AlO）及对比样品（PtK/θ-AlO-N和Pt/θ-AlO）的结构和催化性能进行了分析。根据催化测试，PtK/θ-AlO表现出更好的催化性能，在稳定性测试期间丙烯选择性达到>95%，丙烷产率保持在较高水平（>36%）。观察结果表明，铂基催化剂的初始丙烯选择性与总酸度和强酸位点含量呈负相关。K元素的引入显著降低了催化剂的酸度并提高了丙烯选择性。此外，与K共同引入的Cl的存在提高了催化稳定性，而催化剂酸度的轻微增加则降低了丙烯选择性。PtK纳米颗粒电子密度的富集有助于催化性能的提高。密度泛函理论计算表明，PtK-(100)表面较低的丙烯吸附能和较高的丙烯深度脱氢反应势垒提高了PtK/θ-AlO催化剂的丙烯选择性。
