A substance that speeds up a chemical reaction
a substance that causes or accelerates a chemical reaction without 
itself ... We can, if we like, dispense with the bacteria and speed up the process 
by... [DOC] [TLE] The Effect of Catalysts on Reactions [PAR] A CATALYST is a substance that can speed up a reaction ... A catalytic converter 
is a special device that speeds up the breakdown of harmful chemicals (such... [DOC] [TLE] 5 Things That Speed Up