The invention pertains to an improved apparatus comprised of a monolith catalytic reactor having an inlet and an outlet and a static mixer having an inlet and an outlet thereto with the outlet of said static mixer in communication with the inlet of said monolith catalytic reactor. The invention also pertains to an improvement in a process for effecting a reaction in the monolith catalytic reactor wherein a reactant gas and reactant liquid are introduced to the inlet to the monolith catalytic reactor, reacted and, then, the reaction product passed through the outlet of the monolith catalytic reactor.