Increase of temperature will increase the reaction rate due to
 

An increase in the rate of a reaction for a rise in temperature is due to increase in collision frequency, shortening of mean free path and increase in the number of activated molecules.
Increasing the temperature increases reaction rates because of the disproportionately large increase in the number of high energy collisions. It is only these collisions (possessing at least the activation energy for the reaction) which result in a reaction.