In surface or electrochemical reactions, catalyst immobiliza-tion combines the advantages of homogeneous catalysis andselectivity with the ability to recycle the catalysts. We developedseveral methods−polymerization, noncovalent surface binding,and surface-chemical binding−to prepare “chemically modifiedelectrodes” with reduction of CO 2 as a major target. 6 Surfacebinding can also facilitate electron transfer from the electrode tometal complex catalysts on the surface.