Correlation of the Vanadium Precursor and Structure Performance of Porous VO_X-SiO₂ Solids for Catalytic Dehydrogenation of Propane

Abstract

VO X -SiO 2 catalysts have been synthesized by the one-pot method using different vanadium precursors, namely, ammonium metavanadate (NH 4 VO 3 ; VO 3 − , V 5+ ), vanadium acetylacetonate [V(acac) 3 ; organic complex, V 3+ ], and vanadyl sulfate (VOSO 4 ; VO 2+ , V 4+ ). The influence of different vanadium precursors on the structure−performance relationship of these catalysts is studied on the propane dehydrogenation (PDH) reaction. The catalysts derived from VO 3 − attain a mesoporous structure with fairly high specific surface area and large pore volume, while those prepared with V(acac) 3 or VOSO 4 display a microporous structure. It is noted that VO X -SiO 2 catalysts derived from NH 4 VO 3 present a better catalytic performance, and low-polymerized VO X species display better intrinsic activity compared with isolated species. This study may contribute to the selection of vanadium precursors for the one-pot synthesis.

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).…”

Oxidation of 5-[(Formyloxy)methyl]furfural to Maleic Anhydride with Atmospheric Oxygen Using α-MnO2/Cu(NO3)2 as Catalysts

“…Spurred by this result, we sought to screen a superior catalyst that can enable a facile FMF-to-MA conversion with higher efficiency. As shown in Table , a series of catalysts that are usually used to catalytically cleave a C–C bond and oxidation, such as Fe-, V-, Mo-, and Mn-based oxides or salts, were selected as candidates for the oxidation of FMF to MA. − Most Fe-, V-, and Mo-based catalysts presented high conversion of FMF in 5 h but low yield of MA. Excitingly, separate α-MnO 2 exhibited a moderate MA yield (Table , entry 11).…”

Nano-Hierarchical SSZ-13-Supported Low-Polymerized VOX as Highly Efficient Catalysts for Propane Dehydrogenation

“…Previous studies suggested that the ratio of isolated to polymerized VO X species decreases with the increase of E g values, and the values at 3.0−3.6 eV are attributed to low-polymerized VO X species. 44,49,50 Thus, isolated VO 4 species are dominant in 1V/SSZ possessing the highest E g value (3.79 eV), and with the increase of vanadium loading to 5 wt %, low-polymerized VO X species start to be formed and become prominent. Further increasing vanadium loading to 12 wt % contributes to an obvious decrease of E g values to 2.71 eV and an significant increase of CVB number (calculated based on the empirical equation CVB = −3.95E g + 14.03 established by Wachs and co-workers 51 ) to 3.33 (Table S1), potentially suggesting the formation of numerous highpolymerized VO 5 or VO 6 species for the V 2 O 5 -containing 12V/SSZ catalyst.…”