Facilitating the reduction of V–O bonds on VO_x/ZrO₂ catalysts for non-oxidative propane dehydrogenation

Abstract

Low coordinated VOx species on ZrO2 with more reduced V–O bonds leads to improved catalytic activity for propane dehydrogenation.

Heterogeneous alkane dehydrogenation catalysts investigated via a surface organometallic chemistry approach

“…Pre-treatment by H 2 has been shown to influence the activity, 82 and both V III and V IV isolated sites have been proposed to catalyse this reaction. [82][83][84][85][86][87][88][89][90][91] To gain insight into the active structures for the vanadium catalysed dehydrogenation of propane, silica-supported V III and V V single sites have thus been prepared via SOMC (Scheme 6) using the well-defined V III and V V molecular precursors V III (Mes) 3 (THF) and V V (O)(Mes) 3 . 83,89,92 3).…”

High‐Density Lewis Acid Sites in Porous Single‐Crystalline Monoliths to Enhance Propane Dehydrogenation at Reduced Temperatures

“…In contrast, the non‐oxidative propane dehydrogenation with noble‐metal catalyst like PtSn x gives the conversion of ≈50 % and the propylene selectivity of ≈90 % at ≈600 °C [8–13] . However, operation with non‐noble‐metal catalyst like VO X /Al 2 O 3 and VO X /ZrO 2 leads to a conversion below ≈25 % and a propene selectivity below ≈90 % even at ≈600 °C, while it suffers from serious coke deposition and conversion drop in dozens of minutes [14–17] . For non‐noble metal catalyst, the lack of catalytic activity gives rise to a limited propane conversion at reduced temperatures while the complicated functional groups at surfaces distract the main reaction to generate by‐products including methane, ethane and coke [18] .…”

Design and tailoring of advanced catalytic process for light alkanes upgrading

“…Gong and coworkers found that the VO x supported on ZrO 2 exhibited six times higher catalytic activity than it supported on commercial γ-Al 2 O 3 , ascribed to the interaction between VO x and ZrO 2 for the formation of low coordinated V species with low C H bond activation barrier. 137,138 Laursen and coworkers reported the high propylene selectivity ($94%), activity (TOF = 4.7 × 10 −2 seconds −1 ), as well as stability ($94% for the 82 hours) for the direct propylene dehydrogenation over the Ni 3 Ga/Al 2 O 3 catalyst. 139 Furthermore, a comparison of the well-defined Si-supported Ni 3 Ga and NiGa catalysts as well as Ni 3 Ga/Al 2 O 3 suggested an optimal catalyst composition between 3:1 and 1:1 Ni:Ga, where Ni as the active site for dehydrogenation and the improved conversion, and Ga for the enhanced selectivity and stability.…”

“…As a result, the Cu/ZrO 2 ‐La 2 O 3 catalyst with Cu loading of 0.5 wt% exhibited industrially comparable activity and durability. Gong and coworkers found that the VO x supported on ZrO 2 exhibited six times higher catalytic activity than it supported on commercial γ‐Al 2 O 3 , ascribed to the interaction between VO x and ZrO 2 for the formation of low coordinated V species with low CH bond activation barrier 137, 138 . Laursen and coworkers reported the high propylene selectivity (∼94%), activity (TOF = 4.7 × 10 −2 seconds −1 ), as well as stability (∼94% for the 82 hours) for the direct propylene dehydrogenation over the Ni 3 Ga/Al 2 O 3 catalyst 139 .…”