MnOx catalysts were contrastively prepared by an alkali-promoted redox precipitation strategy (MnOx-RP) and a conventional citrate sol–gel method (MnOx-SG), and tested for the catalytic oxidation of toluene, where MnOx-RP exhibited higher catalytic activity, excellent catalytic durability under dry conditions and good regeneration ability under humid conditions. The characterizations results indicated that different crystalline phases but similar textual properties (specific surface area, porosity and morphology) were observed over MnOx-RP and MnOx-SG catalysts, while MnOx-RP presented significantly higher low-temperature reducibility and average oxidation state of Mn as well as higher abundance of surface adsorbed oxygen species compared with MnOx-SG, thus beneficially resulting in its superior catalytic activity in the reaction.

The carbon-covered aluminas were prepared by using different monocarboxylic acids as carbon sources to modify active alumina, and then were used as supports to prepare supported CoMo catalysts for hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DMDBT). These monocarboxylic acid molecules can be readily converted to carbon species by thermal decomposition in a nitrogen atmosphere and deposited on an alumina surface. The carbon species can then effectively weaken the interaction between active metals and alumina, which improves the migration and growth of surface Mo species. This result further affected the morphology and orientation of surface sulfur species, that is, the slab length and stacking number of the MoS2 slabs, which closely relates to HDS activity. Since the surface Mo species supported on the alumina modified with acetic acid consisted of the MoS2 slabs with the shortest lengths, leading to the presence of more easily reducible sulfur species during the reaction, the corresponding catalyst exhibited the highest HDS activity for 4,6-DMDBT. In addition, the stacking numbers for all of the catalysts were relatively low, which hindered the adsorption of 4,6-DMDBT on the brim sites of the MoS2 stacks, and thus the HDS reaction mainly occurred through the direct desulfurization route.

Molybdenum carbide (Mo2C) catalysts supported on mesoporous carbon (MC) were prepared by the carbothermal hydrogen reduction method. Their properties were characterized by N2 adsorption, XRD and TEM. The Mo2C formation procedure was investigated by TPR and XPS. Methyl stearate was employed as a model compound containing oxygen to investigate the hydrodeoxygenation (HDO) activity of Mo2C/MC catalyst. The results showed Mo2C was formed on MC at the reduction temperature up to 660 °C. The HDO of methyl stearate on Mo2C/MC catalyst occurred through two parallel routes to give the main product octadecane and the by-product heptadecane. 10 wt% Mo2C/MC catalyst exhibited high activity for HDO of methyl stearate with almost 100 % conversion of methyl stearate and high selectivity of 93.6 % toward octadecane, indicating that it is an excellent catalyst to convert vegetable oils into hydrocarbons.

The carbon-covered aluminas were prepared by using different monocarboxylic acids as carbon sources to modify active alumina, and then were used as supports to prepare supported CoMo catalysts for hydrodesulfurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DMDBT). These monocarboxylic acid molecules can be readily converted to carbon species by thermal decomposition in a nitrogen atmosphere and deposited on an alumina surface. The carbon species can then effectively weaken the interaction between active metals and alumina, which improves the migration and growth of surface Mo species. This result further affected the morphology and orientation of surface sulfur species, that is, the slab length and stacking number of the MoS2 slabs, which closely relates to HDS activity. Since the surface Mo species supported on the alumina modified with acetic acid consisted of the MoS2 slabs with the shortest lengths, leading to the presence of more easily reducible sulfur species during the reaction, the corresponding catalyst exhibited the highest HDS activity for 4,6-DMDBT. In addition, the stacking numbers for all of the catalysts were relatively low, which hindered the adsorption of 4,6-DMDBT on the brim sites of the MoS2 stacks, and thus the HDS reaction mainly occurred through the direct desulfurization route.