Non-pretreated catalysts showed better DMF selectivity than pretreated ones.

CuZr catalyst presented the best DMF selectivity probably due to the neutral nature of ZrO₂ and Cu hydrogenation capacity.

The presence of impurities in a real feed reduced the DMF selectivity.

Pressure increase improved H₂ mass transfer, resulting in higher DMF selectivity.

Lower space velocity increased DMF selectivity.