Ethylene and Acetaldehyde Production by Selective Oxidation of Ethanol Using Mesoporous V−MCM-41 Catalysts

Abstract

Vanadium-incorporated MCM-41 type catalytic materials, which were synthesized by a direct hydrothermal synthesis procedure, showed very high activity and high selectivity in the production of ethylene from ethanol in an oxidative process. Ethylene selectivity showed a significant increase with an increase in temperature over 300 °C, while relatively high acetaldehyde selectivities were observed at lower temperatures. An ethylene yield value of 0.66 obtained at 400 °C with an O2/ethanol feed ratio of 0.5 was beneficial from the point of view that these results might open a new pathway for the production of ethylene from a nonpetroleum environmentally friendly feedstock, namely, bioethanol. The optimum V/Si ratio of the catalyst, which gave the maximum ethylene yield, was found to be around 0.04. Experimental results showing the formation of acetaldehyde and not showing the formation of ethylene in the absence of gas-phase oxygen and the catalyst deactivation observed in such conditions suggested a redox mechanism involving the surface lattice oxygen of the catalyst in acetaldehyde production, while the involvement of adsorbed oxygen was concluded to take place in the formation of ethylene.

Spectroscopic investigation into the design of solid–acid catalysts for the low temperature dehydration of ethanol

“…[1] An example of this is the increased need for ethylene, a major precursor for the pharmaceutical and polymer industries. Currently ethylene is produced from steam cracking of fossil fuels, requiring temperatures exceeding 700 o C. [2] However, finite reserves of fossil fuels or shale gas cannot solely sustain such growth indefinitely, [3] inspiring the search for novel precursors. In contrast, biomass-based precursors are considered viable long term options, with bio-ethanol, fermented from sugars, being considered as an alternative feedstock in ethylene production ( Figure 1).…”

Mechanism and Site Requirements for Ethanol Oxidation on Vanadium Oxide Domains

“…9 There have been a number of studies, as well, on the activity of supported vanadia for the oxidative dehydrogenation (ODH) of ethanol to acetaldehyde [10][11][12][13][14][15][16][17][18][19] or acetic acid. 20 These studies have shown that the catalyst activity depends on the nature of the support, and that higher rates are achieved with supports such as Al 2 O 3 , Al 2 O 3 -ZrO 2 , TiO 2 , TiO 2 /SiO 2 , and ZrO 2 -SiO 2 than with SiO 2 .…”

Effect of P Content on the Catalytic Performance of P-modified HZSM-5 Catalysts in Dehydration of Ethanol to Ethylene

“…However, in view of the energy crisis, the production of ethylene from ethanol has received widespread attention in recent years [1][2][3][4][5], as ethanol can be obtained easily from renewable biomass by fermentation.…”