Linear free energy relationships (LFERs) have been used in heterogeneous catalysis for a long time. Their application to heterogeneous catalytic systems have been based on the original substituent concept introduced by Hammett [K.J. Laidler, Chemical Kinetics, Harper Collins Publishers, New York, 1987, pp. 246-151.]. This work deals with the idea of validating a new concept for the application of LFER in heterogeneous catalysis. Following this idea, the considered reactions center is the active site on the catalyst surface, rather than that of the reacting molecule. The confirmation of a successful application to HDS and hydrogenation reaction will be shown as a preliminary example of the potential of the new approach. The implications for catalyst design will be discussed.