Reaction mechanism of methanol to formaldehyde over Fe- and FeO-modified graphene

Methanol oxidative dehydrogenation and dehydration on carbon nanotubes: active sites and basic reaction kinetics

In situ active site titration, carbonyl group containing model catalysts, and kinetic analysis have been applied to reveal the nature of oxidized carbon nanotubes catalyzed methanol dehydration and oxidative dehydrogenation reactions.

Photocatalytic oxidation of methanol to formaldehyde on bismuth-based semiconductors

Methanol is widely applied in photocatalysis as a scavenger of holes, and is also studied as a model system for heterogeneous photocatalysis for the production of formaldehyde. Compared to commercial processes for formaldehyde production via thermal catalytic methanol oxidation, photocatalytic oxidation of methanol to formaldehyde may be more promising when considering the following aspects: 1) lower reaction temperature and pressure (generally operated at room temperature and ambient pressure); 2) lower cost of the energy source (such as solar light) and 3) easy-to-design reactive system. Photocatalytic methanol oxidation was carried out using four different bismuth-based semiconductors (BBS), Bi₂WO₆, Bi₂MoO₆, BiOBr and BiVO₄, under varying system temperature (5-50 °C), bubbling speed (0.1-1.0 LPM), catalyst dosage (0.2-2.0 g/L), and initial methanol concentration (12.5-250 mM). It was found that the formaldehyde formation rate for all photocatalysts increased as a function of each of these system parameters. Of these four BBS, it was found that Bi₂WO₆ had the highest formaldehyde formation rate (0.081 mM/h). This work provides a new approach to produce formaldehyde using photocatalysis, and future work has also been proposed.

Efficient reduction of formic acid to formaldehyde by zinc

The possibility of thermally reducing formic acid to formaldehyde selectively has been probed using metallic zinc. Good selectivity (over 80%) was obtained with low concentrations of formic acid, with methanol and methyl formate as secondary products. The selectivity can be tuned by changing the carrier gas flow, temperature, and zinc amount. Zinc was oxidized to zinc oxide during this process.

Magnetically Recoverable Catalysts: Beyond Magnetic Separation

Here, we discuss several important aspects of magnetically recoverable catalysts which can be realized when magnetic oxide nanoparticles are exposed to catalytic species and catalytic reaction media. In such conditions magnetic oxides can enhance performance of catalytic nanoparticles due to (i) electronic effects, (ii) catalyzing reactions which are beneficial for the final reaction outcome, or (iii) providing a capacity to dilute catalytic metal oxide species, leading to an increase of oxygen vacancies. However, this approach should be used when the magnetic oxides are stable in reaction conditions and do not promote side reactions. Incorporation of another active component, i.e., a graphene derivative, in the magnetically recoverable catalyst constitutes a smart design of a catalytic system due to synergy of its components, further enhancing catalytic properties.

Metal oxide–zeolite composites in transformation of methanol to hydrocarbons: do iron oxide and nickel oxide matter?

Novel, hierarchical zeolites modified with both Fe₃O₄ and Ni_xO_y nanoparticles have been developed and studied in the methanol-to-hydrocarbon process.