Question

short note on controlled oxidation ​

Answer 1

Answer:

Catalytic oxidation are processes that oxidize compounds using catalysts. Common applications involve oxidation of organic compounds by the oxygen in air. Such processes are conducted on a large scale for the remediation of pollutants, production of valuable chemicals, and the production of energy.[1] In petrochemistry, high-value intermediates such as carboxylic acids, aldehydes, ketones, epoxides, and alcohols are obtained by partial oxidation of alkanes and alkenes with dioxygen. These intermediates are essential to the production of consumer goods. Partial oxidation presents two challenges. The first is that the most favored reaction between oxygen and hydrocarbons is combustion. The second challenge is the considerable difficulty to activate dioxygen, viz. the splitting of the molecule into its constituent atoms, which has an energy barrier of 498 kJ/mol. The usual strategy to activate oxygen in a controlled manner is to use molecular hydrogen or carbon monoxide as sacrificial reductants in presence of a heterogeneous catalyst, such that the activation barrier is lowered to < 10 kJ/mol and hence milder reaction conditions are required.[2]

One of the most challenging selective oxidations, which has been achieved with supported gold catalysts, is the epoxidation of propylene.

An illustrative catalytic oxidation is the conversion of methanol to the more valuable compound formaldehyde using oxygen in air:

2 CH3OH + O2 → 2CH2O + 2 H2O

This conversion is very slow in the absence of catalysts. Typical oxidation catalysts are metal oxides and metal carboxylates.