Catalytic oxidation
Removing hydrogen from methanol creates a carbonyl while retaining its single carbon. Oxygen accepts the removed hydrogen as water in this overall catalytic-oxidation equation.
- Reagents
- O2; silver-based catalyst
- Conditions
- Vapour-phase catalytic oxidation at elevated temperature
- Reaction class
- Catalytic oxidation
- Equation
- 2CH3OH + O2 -> 2HCHO + 2H2O
Overview
Removing hydrogen from methanol creates a carbonyl while retaining its single carbon. Oxygen accepts the removed hydrogen as water in this overall catalytic-oxidation equation.
Transformation
- Equation
- 2CH3OH + O2 -> 2HCHO + 2H2O
- Reactants
- 2 Methanol + Oxygen
- Products
- 2 Methanal + 2 Water
- Reagents
- O2; silver-based catalyst
- Environment
- Vapour-phase catalytic oxidation at elevated temperature
- Reaction class
- Catalytic oxidation
- Mechanism
- surface-catalysed oxidative dehydrogenation
- Evidence level
- source-backed molecular example
Scope and limitations
- Scope
- Methanol is the one-carbon alcohol; methanal is formaldehyde.
- Limitations
- The equation gives net oxidative dehydrogenation, not complete combustion. Selectivity depends on catalyst and operating conditions.
Related reactions
- Grignard addition co reactant: Methanal → Primary alcohols
Methanal plus a Grignard reagent gives a primary alcohol after acidic work-up.
- Carbonyl reduction: Methanal → Methanol
Hydride addition forms a new C-H bond and converts the C=O pi bond into an alkoxide. Protonation then gives methanol without introducing another carbon.
- Aldehyde oxidation: Methanal → Methanoic acid
Oxidation changes the aldehyde hydrogen into acid functionality through the hydrated carbonyl. The carbon count stays at one, but further oxidation remains possible.
- Esterification: Methanol → Methyl acetate
Methanol attacks an acid-activated carbonyl; proton transfers and water loss give methyl acetate. The ester oxygen linking to the methyl group comes from the alcohol.
- Acid hydrolysis: Methyl acetate → Methanol
Water adds to the protonated ester carbonyl. Proton transfer allows methanol to leave as the carbonyl reforms, producing the acid and alcohol together.
References
- Supported silver and copper catalysts in the oxidative dehydrogenation of methanol to formaldehyde: a comparative study under industrially relevant conditionsFabian Eichner; Emre Turan; Jörg Sauer; Michael Bender; Silke Behrens · Catalysis Science & Technology · 2023
Publisher abstract checked 2026-09-16: silver-catalysed methanol oxidative dehydrogenation to formaldehyde.