A vanadium phosphorus oxide catalyst synthesized in rotating packed bed for high‐efficiency selective oxidation of n‐butane

Abstract

Oxidation of n‐butane to produce maleic anhydride (MA) by the vanadium phosphorus oxide (VPO) catalyst is important for the fine chemical industry. However, the improvement in MA yield exceeding 60% is still a big challenge. In this article, a VPO catalyst with increased MA yield originated from the tailored structure of VPO precursor prepared in a rotating packed bed (RPB) reactor with excellent micro‐mixing efficiency. The activated VPO‐RPB catalyst displayed the coexistence of X1‐VOPO4 and αI‐VOPO4 phases and enhanced reducibility of V4+ state. Remarkably, the MA yield in n‐butane oxidation catalyzed by VPO‐RPB reached up to 66%, showing an increment by 14% compared with VPO‐STR prepared in a stirring tank reactor (STR). The VPO‐RPB showed the repeatable catalytic performance and achieved a promising scale‐up production. This work provides the experimental evidence of a dual‐phase (X1‐VOPO4 and αI‐VOPO4) mechanism for n‐butane oxidation, and reveals the structure–activity dependence of VPO catalyst.

CoN graphene encapsulated cobalt catalyst for H2O2 decomposition under acidic conditions

“…When above 2 M H 2 O 2 , the H 2 O 2 reaction solution gradually turns yellow due to the sulfonation and oxidation of the carbon in the Co@CN. The fast reaction speed and the stability of Co@CN material prompted us to adopt a simple continuous flow system to facilitate the automation of the reaction device and the immediate control of reaction parameters 28 . Experimental Settings are shown in Figure 2C.…”

Influence of the Structural Characteristics of VPO Catalysts on the Temperature Sensitivity of the Oxidation Reaction of n-Butane to Maleic Anhydride

“…), such positive tetravalent vanadium species can hinder n -butane oxidation reactions. − Therefore, to facilitate the n -butane oxidation reaction, the P/V ratio needs to be controlled within a reasonable range, and a lower P/V ratio is beneficial for improving the temperature sensitivity of the n -butane conversion rate. (2) The synergy between different positive pentavalent vanadium species and (VO) 2 P 2 O 7 is conducive to the smooth progress of the n -butane oxidation reaction . However, different positive pentavalent vanadium species can also transform into each other at different temperatures, that is, in the whole process of different vanadium species during the n -butane oxidation reaction .…”

“…(2) The synergy between different positive pentavalent vanadium species and (VO) 2 P 2 O 7 is conducive to the smooth progress of the n-butane oxidation reaction. 69 However, different positive pentavalent vanadium species can also transform into each other at different temperatures, that is, in the whole process of different vanadium species during the n-butane oxidation reaction. 42 (3) Changes in the lattice oxygen in the catalyst, as well as isolated V 5+ species, play an important role in catalytic reactions, and isolated V 5+ hinders lattice oxygen conversion, 70−72 thereby reducing the temperature sensitivity of MA selectivity.…”

Regulation of Maleic Anhydride Selectivity for n-Butane Oxidation by Sb2O3-Modified Vanadium Phosphorus Oxide Catalysts

“…Therefore, a suitable V 4+ /V 5+ ratio can be achieved by adjusting the doping amount, thus significantly improving the MA selectivity. Besides, many strategies such as regulating the structure, morphology, P/V ratio, lattice oxygen (Lat-O), and surface oxygen (Sur-O) are also proposed to improve the physiochemical properties of VPO catalysts and MA yields. ,− The first step of selective oxidation of n -butane is the dehydrogenation of n -butane to produce olefins, which is greatly influenced by the surface acidity of the VPO catalyst . The second step is the epoxidation of the generated olefins, in which olefins further combine with Lat-O in the VPO to form MA .…”