ZnO Nanoclusters Supported on Dealuminated Zeolite β as a Novel Catalyst for Direct Dehydrogenation of Propane to Propylene

Abstract

Small ZnO nanoclusters supported on dealuminated β zeolite were prepared and evaluated for catalyzing direct dehydrogenation of propane to propylene (PDH), exhibiting high catalytic performance. N2 sorption, XRD, TEM, 27Al and 28Si MAS NMR, IR, XRF, DR UV‐vis, XPS, and NH3‐TPD techniques were employed to characterize the physicochemical properties of this novel catalyst system. It is found that the Zn species can be accommodated in the vacant T‐atom sites of dealuminated β zeolite due to the reaction of aqueous zinc acetate solution with silanol groups, and thus, producing massive small ZnO nanoclusters as active phases in PDH. Additionally, dealuminated β zeolite can greatly depress side reactions attributable to the absence of strong acid sites, thereby guaranteeing high catalytic activity, propylene selectivity and stability. As a result, the optimal catalyst of 10 wt% Zn loaded on dealuminated β zeolite exhibits a high initial propane conversion of around 53 % and a superior propylene selectivity of about 93 % at a space velocity of 4000 cm3 gcat−1 h−1, together with the high stability and satisfactory reusability. This study may open a new way to design and synthesize highly active PDH catalysts with high selectivity and stability.

Nature of active phase of VO catalysts supported on SiBeta for direct dehydrogenation of propane to propylene

“…Further increasing V loading cannot improve the catalytic activity is because the largest amount of V-O-Si bridges are existent on the 3VSiBeta. Similar result was reported by our group recently, where the ZnO supported on SiBeta could create acidic Zn-O-Si bonds which are active for catalyzing the PDH reaction [52]. In addition, there is no evident correlation between the propylene selectivity and the number of acidic sites, as seen in Fig.…”

Design of PtZn nanoalloy catalysts for propane dehydrogenation through interface tailoring via atomic layer deposition

“…Previous studies reported that Zn 2+ species are active in propane dehydrogenation. 26,28,[44][45][46][47] However, homogeneously coated Zn ALD /SiO 2 performed not very well and cannot be considered a relevant catalyst. Pt nanoparticles supported on SiO 2 without ZnO exhibited a fast decrease of activity and selectivity.…”

“…24,25 Single site Zn 2+ species and ZnO nanoclusters were investigated for activation of C-H bonds. [26][27][28] However, single site Zn 2+ species and ZnO nanoclusters are unstable under the harsh conditions of PDH. Many strategies have been applied to form bimetallic Pt/Zn nanoparticles.…”

State-of-the-art catalysts for direct dehydrogenation of propane to propylene

“…Supported Zn oxides are also reported to be active for PDH [84][85][86][87]163]. Schweitzer et al [85] developed a strong electrostatic adsorption methodology to synthesize SiO2-supported single site Zn 2+ catalysts.…”