Propane dehydrogenation (PDH) to propene is an important alternative to oil-based cracking processes, to produce this industrially important platform chemical1,2. The commercial PDH technologies utilizing Cr-containing (refs. 3,4) or Pt-containing (refs. 5–8) catalysts suffer from the toxicity of Cr(vi) compounds or the need to use ecologically harmful chlorine for catalyst regeneration9. Here, we introduce a method for preparation of environmentally compatible supported catalysts based on commercial ZnO. This metal oxide and a support (zeolite or common metal oxide) are used as a physical mixture or in the form of two layers with ZnO as the upstream layer. Supported ZnOx species are in situ formed through a reaction of support OH groups with Zn atoms generated from ZnO upon reductive treatment above 550 °C. Using different complementary characterization methods, we identify the decisive role of defective OH groups for the formation of active ZnOx species. For benchmarking purposes, the developed ZnO–silicalite-1 and an analogue of commercial K–CrOx/Al2O3 were tested in the same setup under industrially relevant conditions at close propane conversion over about 400 h on propane stream. The developed catalyst reveals about three times higher propene productivity at similar propene selectivity.
The use of renewable energy is central for the realization of a circular economy, which is essential for further global economic development. In this background, hydrogen storage materials play an important role. Here we propose a previously overlooked, industrially available bulk chemical (methyl formate, MF) as an efficient and practical hydrogen storage material. Utilizing appropriate catalysts, hydrogen production from MF is significantly faster than with other established chemical hydrogen carriers, such as formic acid and methanol, under very mild conditions. The optimized MF dehydrogenation system presented here is highly active (maximum turnover frequency (TOFmax) > 44,000 h−1 and turnover number > 100,000) and selective (CO undetectable). Moreover, the solvent-free MF dehydrogenation demonstrates its application potential. Here we show the dehydrogenation reaction of MF. We expect that these insights will serve as an inspiration for the development of alternative energy materials and new catalytic transformations.
Photoelectron spectroscopy and theoretical calculations show that the global minimum of the B48−cluster has a bilayer structure, suggesting the viability of bilayer borophenes.
18 January 2023 in Journal of the American Chemical Society