Searles Keith, Chan Ka Wing, Mendes Burak Jorge Augusto, Zemlyanov Dmitry, Safonova Olga, Copéret Christophe
ETH Zürich, Department of Chemistry and Applied Biosciences, Vladimir Prelog Weg 1-5 , ETH Zürich , CH-8093 Zurich , Switzerland.
Birck Nanotechnology Center , Purdue University , 1205 West State Street , West Lafayette , Indiana 47907 , United States.
J Am Chem Soc. 2018 Sep 19;140(37):11674-11679. doi: 10.1021/jacs.8b05378. Epub 2018 Sep 11.
The development of more effective alkane dehydrogenation catalysts is a key technological challenge for the production of olefins from shale gas, an abundant source of light hydrocarbons. Surface organometallic chemistry provides an original approach to generate nanometric Ga-Pt bimetallic particles supported on partially dehydroxylated silica containing gallium single-sites, which displays high activity, selectivity, and stability in propane dehydrogenation. This catalyst was prepared via sequential grafting of a platinum precursor onto silica possessing site-isolated gallium sites followed by H reduction. Monitoring generation of the reduced species, GaPt/SiO, via in situ X-ray absorption spectroscopy reveals formation of a Ga Pt (0.5 < x < 0.9) alloy with a fraction of gallium remaining as isolated sites. This bimetallic material exhibits catalytic performance that far surpasses each of the individual components and other reported Ga-Pt based catalysts; this is attributed to the highly dispersed Ga Pt alloyed structure on a support with low Brønsted acidity containing gallium single-sites.
开发更有效的烷烃脱氢催化剂是利用页岩气(一种丰富的轻质烃来源)生产烯烃的关键技术挑战。表面有机金属化学提供了一种原始方法,可生成负载在含有镓单中心的部分脱羟基二氧化硅上的纳米级镓 - 铂双金属颗粒,该颗粒在丙烷脱氢中表现出高活性、选择性和稳定性。这种催化剂是通过将铂前驱体依次接枝到具有位点隔离镓位点的二氧化硅上,然后进行氢气还原制备而成。通过原位X射线吸收光谱监测还原物种GaPt/SiO的生成,揭示了形成了GaPt(0.5 < x < 0.9)合金,其中一部分镓保留为孤立位点。这种双金属材料表现出的催化性能远远超过了每个单独的组分以及其他报道的基于镓 - 铂的催化剂;这归因于在含有镓单中心、低布朗斯台德酸度的载体上高度分散的GaPt合金结构。