CoO_x within dealuminated Beta (SiBeta) zeolite developing into ultrasmall-sized Co particles under H₂ or reactant gas is highly efficient for catalyzing direct dehydrogenation of propane (PDH) to propylene reaction. The existence of highly dispersed CoO_x species is identified, and the easily reducible CoO_x species are confined in the created T-sites (silanols) of SiBeta support. The CoSiBeta catalysts with or without prereduction treatments show similar catalytic performance but different induction periods, implying that the metallic Co formed in situ during the reaction are the active sites. Co in SiBeta zeolite (0.5 wt%) showed state-of-the-art propylene productivity with propane conversion of about 72% and propylene selectivity of over 92% at 600 °C, which is far better than that of the other reported Co catalysts and comparable to that of industrial catalysts. This work proves the high catalytic ability and product selectivity of small confined Co particles, as well as providing novel inspiration for the design of low-cost, ecofriendly, and advanced catalysts for PDH.

在H ₂或反应气体下，脱铝的Beta（SiBeta）沸石中的CoO _x变成超小型Co颗粒对于催化丙烷（PDH）的直接脱氢反应成丙烯反应非常有效。确定了高度分散的CoO _x物种的存在，以及易于还原的CoO _x物种被限制在SiBeta支持物的T型位点（硅烷醇）中。经过或未经过预还原处理的CoSiBeta催化剂显示出相似的催化性能，但诱导时间不同，这表明反应过程中原位形成的金属Co是活性位点。SiBeta沸石中的Co（0.5 wt％）显示出最先进的丙烯生产率，在600°C时丙烷转化率约为72％，丙烯选择性超过92％，远优于其他报道的Co催化剂与工业催化剂相当。这项工作证明了较小的受限Co颗粒的高催化能力和产物选择性，并为设计低成本，环保和先进的PDH催化剂提供了新的启示。