MXene Aerogel Derived Ultra-Active Vanadia Catalyst for Selective Conversion of Sustainable Alcohols to Base Chemicals

Abstract

Selective oxidation reactions are an important class of the current chemical industry and will be highly important for future sustainable chemical production. Especially, the selective oxidation of primary alcohols is expected to be of high future interest, as alcohols can be obtained on technical scales from biomass fermentation. The oxidation of primary alcohols produces aldehydes, which are important intermediates. While selective methanol oxidation is industrially established, the commercial catalyst suffers from deactivation. Ethanol selective oxidation is not commercialized but would give access to sustainable acetaldehyde production when using renewable ethanol. In this work, it is shown that employing 2D MXenes as building blocks allows one to design a nanostructured oxide catalyst composed of mixed valence vanadium oxides, which outperforms on both reactions known materials by nearly an order of magnitude in activity, while showing high selectivity and stability. The study shows that the synthesis route employing 2D materials is key to obtain these attractive catalysts. V 4 C 3 T x MXene structured as an aerogel precursor needs to be employed and mildly oxidized in an alcohol and oxygen atmosphere to result in the aspired nanostructured catalyst composed of mixed valence VO 2 , V 6 O 13 , and V 3 O 7 . Very likely, the bulk stable reduced valence state of the material together coupled with the nanorod arrangement allows for unprecedented oxygen mobility as well as active sites and results in an ultra-active catalyst.

Flexible High-Performance and Screen-Printed Symmetric Supercapacitor Using Hierarchical Rodlike V3O7 Inks

“…As a pseudocapacitive material, vanadium oxides (e.g., V 3 O 7 , V 2 O 5 , VO 2 , and V 2 O 3 ) store/release charges by adsorption/desorption or/and intercalation/de-intercalation processes followed by redox reactions [ 19 ], resulting in an extremely fast charge/discharge rate, which enables storing and releasing more energy [ 20 , 21 ]. Among these, V 3 O 7 with mixed valence states is considered to be a promising electrode material on account of the outstanding theoretical specific capacitance [ 22 ]. In addition, the unique physicochemical construction generates the ability to act as a positive and negative material synchronously, which can effectively solve the problem of charge non-conservation.…”