Characterization and performance of sulfated VOx–TiO2 catalysts in the one-step oxidation of methanol to dimethoxymethane

The sulfated VOx–TiO2 catalysts were synthesized by rapid combustion method. The catalytic properties were evaluated by the one-step oxidation of methanol to dimethoxymethane. It was found that the sulfate was highly dispersed on the catalyst surface as the sulfate content below 4 mol%, and aggregated as it was above 4 mol%. The former contributed to the increased number of acidic sites, while the latter decreased the number of acidic sites. The highest DMM selectivity (91.76%) was obtained with the sulfate content at 4 mol%, which should be attributed to its largest number of acidic sites and stronger reducibility.