A process and a catalyst reaction zone comprising one or more fixed bed reactors
for oxidizing methanol in a reactant gas feed stream to formaldehyde. According
to one embodiment, the process comprises introducing the reactant gas feed stream
into an upstream region containing a vanadia-titania first catalyst (substantially
free of a volatile MoO3 species) under oxidizing conditions to form
a partially oxidized reactant gas feed stream which is then introduced under oxidizing
conditions into a downstream region containing a metal molybdate second catalyst
to further oxidize any residual methanol contained therein. According to another
embodiment, a fixed bed reactor comprising an upstream region and a downstream
region containing the aforementioned vanadia-titania and metal molybdate catalysts,
respectively, is utilized to implement the inventive process to yield a product
gas stream containing formaldehyde preferably at a conversion of 85% or more and
a selectivity of 90% or more.