Ethanol Dehydration over WO₃/TiO₂Catalysts Using Titania Derived from Sol-Gel and Solvothermal Methods

Abstract

The present study aims to investigate the catalytic ethanol dehydration to higher value products including ethylene, diethyl ether (DEE), and acetaldehyde. The catalysts used for this reaction were WO3/TiO2 catalysts having W loading of 13.5 wt.%. For a comparative study, the TiO2 supports employed were varied by two different preparation methods including the sol-gel and solvothermal-derived TiO2 supports, denoted as TiO2-SG and TiO2-SV, respectively. It is obvious that the different preparation methods essentially altered the physicochemical properties of TiO2 supports. It was found that the TiO2-SV exhibited higher surface area and pore volume and larger amounts of acid sites than those of TiO2-SG. As a consequence, different characteristics of support apparently affected the catalytic properties of WO3/TiO2 catalysts. As expected, both catalysts WO3/TiO2-SG and WO3/TiO2-SV exhibited increased ethanol conversion with increasing temperatures from 200 to 400°C. It appeared that the highest ethanol conversion (ca. 88%) at 400°C was achieved by the WO3/TiO2-SV catalysts due to its high acidity. It is worth noting that the presence of WO3 onto TiO2-SV yielded a remarkable increase in DEE selectivity (ca. 68%) at 250°C. In summary, WO3/TiO2-SV catalyst is promising to convert ethanol into ethylene and DEE, having the highest ethylene yield of ca. 77% at 400°C and highest DEE yield of ca. 26% at 250°C. These can be attributed to proper pore structure, acidity, and distribution of WO3.

TiO2-Based Water-Tolerant Acid Catalysis for Biomass-Based Fuels and Chemicals

“…An incipient wet impregnation or ionic exchange method can be used for the preparation of WO 3 –TiO 2 by doping TiO 2 rutile with WCl 6 or H 2 WO 4 in 30% (v/v) H 2 O 2 solution, followed by centrifugation, drying, and calcination (ca. 400 or 600 °C). , Hydrothermal treatment of metal precursors, namely, ammonium metatungstate and titanium sulfate in oxalic acid at 175 °C for 24 h, with subsequent filtration, drying, and calcination (ca. 400 °C) can furnish layered-type W–Ti oxides .…”

“…400 or 600 °C). 63,64 Hydrothermal treatment of metal precursors, namely, ammonium metatungstate and titanium sulfate in oxalic acid at 175 °C for 24 h, with subsequent filtration, drying, and calcination (ca. 400 °C) can furnish layered-type W−Ti oxides.…”

Catalyst Recycling in the Reactive Distillation of Primary Alcohols to Olefins Using a Phosphoric Acid Catalyst

“…The conversion of ethanol to ethylene has seen significant interest as ethanol is available from the biomass fermentation of glucose. Many processes are heterogeneously catalyzed gas-phase reactions using, for example, zeolites (ZSM-5) or WO 3 immobilized on TiO 2 . − Besides ethanol, longer chain primary alcohols have been dehydrated to form the corresponding olefins such as butanol to butene . Fatty alcohols from bio-oils can also be dehydrated, as shown by Echaroj et al , using γ -alumina to dehydrate 1-decanol to decenes and decylether .…”

Multiple Cuprous Centers Supported on a Titanium-Based Metal–Organic Framework Catalyze CO2 Hydrogenation to Ethylene

“…C 2 H 5 OH dehydration to generate C 2 H 4 has been well established with Lewis acid and Brönsted acid catalysts. Ti IV is a strong Lewis acid that can catalyze C 2 H 5 OH dehydration to generate C 2 H 4 . , …”

“…C 2 H 5 OH dehydration to generate C 2 H 4 has been well established with Lewis acid 23 and Bronsted acid 24 Ti IV is a strong Lewis acid that can catalyze C 2 H 5 OH dehydration to generate C 2 H 4 . 25,26 In this work, we supported Cu I centers on a Ti-based MOF, MIL-125, to obtain a high density of uniform active sites throughout the MOF. 27 The μ 2 -OH groups in the Ti 8 (μ 2 -O) 8 (μ 2 -OH) 4 secondary building units (SBUs) of MIL-125-NH 2 were deprotonated with LiCH 2 SiMe 3 to give μ 2 -O − Li + sites, which were further metalated with Cu I to form μ 2 -O − Cu I .…”