中国石油大学姜桂元团队报道了用于丙烷高效脱氢反应的ZnOx物种的原位生成。相关研究成果发表在2021年11月10日出版的国际学术期刊《自然》。
丙烷脱氢（PDH）制丙烯是油基裂解工艺的重要替代方法，用于生产这一工业上重要的平台化学品。使用含铬或含铂催化剂的商用PDH技术受到Cr(VI)化合物毒性的影响，或需要使用对生态有害的氯进行催化剂再生。
该文中，研究人员介绍了一种基于商用氧化锌制备环境相容性负载型催化剂的方法。该金属氧化物和载体（沸石或普通金属氧化物）用作物理混合物或以ZnO作为上游层的两层形式使用。在550℃以上还原处理后，通过载体OH基团与ZnO生成的Zn原子反应原位形成负载型ZnOx物种。使用不同的互补表征方法，研究人员确定了缺陷OH基团对形成活性ZnOx物种的决定性作用。
出于基准测试目的，在工业相关条件下，在丙烷流上进行近400 h的丙烷转换，在同一装置中测试了开发的ZnO–silicalite-1和商业K–CrOx/Al2O3的类似物。所开发的催化剂显示，在丙烯选择性相似的情况下，丙烯产率高出约三倍。
附：英文原文
Title: In situ formation of ZnOx species for efficient propane dehydrogenation
Author: Zhao, Dan, Tian, Xinxin, Doronkin, Dmitry E., Han, Shanlei, Kondratenko, Vita A., Grunwaldt, Jan-Dierk, Perechodjuk, Anna, Vuong, Thanh Huyen, Rabeah, Jabor, Eckelt, Reinhard, Rodemerck, Uwe, Linke, David, Jiang, Guiyuan, Jiao, Haijun, Kondratenko, Evgenii V.
Issue&Volume: 2021-11-10
Abstract: Propane dehydrogenation (PDH) to propene is an important alternative to oil-based cracking processes, to produce this industrially important platform chemical1,2. The commercial PDH technologies utilizing Cr-containing (refs. 3,4) or Pt-containing (refs. 5,6,7,8) catalysts suffer from the toxicity of Cr(VI) compounds or the need to use ecologically harmful chlorine for catalyst regeneration9. Here, we introduce a method for preparation of environmentally compatible supported catalysts based on commercial ZnO. This metal oxide and a support (zeolite or common metal oxide) are used as a physical mixture or in the form of two layers with ZnO as the upstream layer. Supported ZnOx species are in situ formed through a reaction of support OH groups with Zn atoms generated from ZnO upon reductive treatment above 550°C. Using different complementary characterization methods, we identify the decisive role of defective OH groups for the formation of active ZnOx species. For benchmarking purposes, the developed ZnO–silicalite-1 and an analogue of commercial K–CrOx/Al2O3 were tested in the same setup under industrially relevant conditions at close propane conversion over about 400h on propane stream. The developed catalyst reveals about three times higher propene productivity at similar propene selectivity.
DOI: 10.1038/s41586-021-03923-3
Source: https://www.nature.com/articles/s41586-021-03923-3