NOVELTY - A heterogeneous catalyst comprises a d-block transition metal; and neutrally charged ligand.    USE - The heterogeneous catalyst, system, and methods are useful for oxidizing water; oxidizing organic species; reducing metal ions to their corresponding metallic neutral state; reducing organic species by electrolysis; and for reducing oxygen to water in electrochemical fuel cell, oxygen detector or oxygen scavenging device (all claimed). The catalyst can also be used for incorporating into the oxygen-consuming cathode of a variety of devices including, but not limited to, oxygen-scavenging devices, oxygen-detectors, and fuel cells or batteries which consume oxygen (pure, or in mixtures, such as air, or specialty gas mixtures) in addition to any fuel including, but not limited to, hydrogen, organic fuels, metallic fuels, or inorganic fuels.    ADVANTAGE - The catalysts are prepared from abundant, cost effective metals, such as cobalt, nickel, chromium, manganese, iron, and copper, and contain neutrally charged ligands (e.g. monodentate, bidentate, and/or polydentate ligands). Additionally, the catalysts are stable and active at neutral pH and in a wide range of buffers that are both weak and strong proton acceptors. While its activity is slightly lower than state of the art cobalt-based water oxidation catalysts under some conditions, it is capable of sustaining electrolysis at high applied potentials without a significant degradation in catalytic current. This enhanced robustness gives it an advantage in industrial and large-scale water electrolysis schemes. Being potent enough to oxidize water, the catalysts are also capable of oxidizing a wide range of organic compounds with applications toward oxidative synthesis of specialized chemicals, as well as degradation of harmful organic species.    DETAILED DESCRIPTION - A heterogeneous catalyst comprises chemical formula MY'a(CO)bOc(OH)d(H2O)e.    M=a d-block transition metal;    Y'=a monodentate ligand, bidentate ligand, polydentate ligand, or its combinations;    a and b=0-3;    c=1-4;    d=0-4; and    e=0-6.    INDEPENDENT CLAIMS are included for:    (1) a system comprising a substrate and the catalyst, where the catalyst is in the form of a layer, coating, or particles strongly bound to the substrate and retains its activity;    (2) a method of oxidizing water which involves contacting water with the catalyst or with the system;    (3) a method of oxidizing an organic species which involves contacting the bond to be oxidized with the catalyst or with the system;    (4) a method for reducing metal ions to their corresponding metallic neutral state, which involves oxidizing water with the catalyst or with the system at an anode and reducing the metal ions to their corresponding metallic neutral state at a cathode;    (5) a method for reducing organic species by electrolysis, which involves oxidizing water with the catalyst or with the system at an anode and reducing the organic species at a cathode; and    (6) a method for reducing oxygen to water in an electrochemical fuel cell, oxygen detector or oxygen scavenging device, which involves using the catalyst or the system.