A catalytic process selectively produces ethanol by contacting synthesis
gas (syngas), composed primarily of hydrogen and carbon monoxide, with
three catalysts within a reactor. The first catalyst is a hydrogenation
promoter comprising Cu--Zn, Mo or Fe with an optional alkali metal
additive and an optional support of aluminum oxide, silica, zeolite or
clay. The second catalyst is a homologation promoter comprising one or
more of the Group VIII metals in free or combined form with a co-catalyst
metals consisting of Y or lanthanide or actinide series metals with
optional additives and support. The third catalyst is a hydrogenation
promoter. This series of catalysts improves the selectivity and yield for
ethanol from syngas.