Step 1: This is the controlled oxidation of alkanes.
Step 2: Methane/alkanes oxidized in the presence of Molybdenum oxide ($Mo_2O_3$) yield aldehydes.
Step 3: Specifically, $CH_4 + O_2 \xrightarrow{Mo_2O_3} HCHO + H_2O$. This applies to higher alkanes to form the corresponding aldehyde.
*Note: Copper yields alcohols, and Manganese acetate yields carboxylic acids.*