Abstract:

Catalytic dehydrogenation is an effective pathway to convert low-carbon hydrocarbons into mono-olefins with the same carbon numbers and hydrogen. Due to their low cost and environmental friendliness, Co-based catalysts hold great potential for application in propane catalytic dehydrogenation. In this study, SBA-15 molecular sieves were synthesized via a hydrothermal method, and the carrier surface was loaded with 2.0% Co and different amounts of Mg were added to prepare Co-xMg/SBA-15 catalysts using the incipient wetness impregnation technique for the direct dehydrogenation of propane to propylene. Magnesium, serving as a promoter, formed a stable Co-O-Mg structure with Co, making it difficult to reduce the primary active site Co²⁺. Simultaneously, the addition of Mg increased the total basicity of the catalyst, which favored the adsorption of propane and the desorption of propylene, thereby enhancing the conversion rate, reducing coke deposition, and maintaining good activity and stability of the catalyst. The optimal Mg doping amount was 2%, yielding an initial propane conversion rate of 40.78% and 32.86% after 10h, and the highest propylene selectivity, with an initial one of 93.94% and 91.85% after 10h.

Key words: petroleum, propane dehydrogenation, support, SBA-15, catalyst

摘要：

催化脱氢是将低碳烃类转化为具有相同碳数单烯烃和氢气的有效途径之一。Co基催化剂由于其廉价和环保的优点，在丙烷催化脱氢中具有较大的应用潜力。本文采用水热合成法制备了SBA-15分子筛，在载体表面用等体积浸渍法负载质量分数2.0% Co和不同Mg质量分数得到Co-xMg/SBA-15催化剂，用于丙烷直接脱氢制丙烯反应。Mg作为助剂能与Co形成稳定的Co-O-Mg结构，使主要活性位点Co²⁺难以还原；同时，Mg的加入增加催化剂总碱度，有利于丙烷的吸附和丙烯的脱附，提高转化率，减少积炭，使催化剂保持良好的活性和稳定性。2% Mg为最佳掺入量，丙烷初始转化率为40.78%，在反应10h后转化率为32.86%，在该系列催化剂中具有最高丙烯选择性，初始选择性93.94%，在反应10h后选择性91.85%。

关键词: 石油, 丙烷脱氢, 载体, SBA-15, 催化剂