In surface or electrochemical reactions, catalyst immobilization combines the advantages of homogeneous catalysis and selectivity with the ability to recycle the catalysts. We developed several methods−polymerization, noncovalent surface binding,and surface-chemical binding−to prepare “chemically modified electrodes” with reduction of CO 2 as a major target. 6 Surface binding can also facilitate electron transfer from the electrode to metal complex catalysts on the surface.