Electrocatalysis nickel oxide

Electrocatalysis in oxidation has apparently first been shown for ascorbic acid oxidation by Prussian blue [60] and later by nickel hexacyanoferrate [61]. More valuable for analytical applications was the discovery in the early 1990s of the oxidation of sulfite [62] and thiosulfate [18, 63] at nickel [62, 63] and also ferric, indium, and cobalt [18] hexacyanoferrates. More recently electrocatalytic activity in thiosulfate oxidation was shown also for zinc [23] hexacyanoferrate. Prussian blue-modified electrodes allowed sulfite determination in wine products [64], which is important for the wine industry. 

Also for cathodic oxygen reduction in low-temperature fuel cells, platinum is indispensible as a catalyst whereas the cathodic electrocatalysts in MCFCs and SOFCs are lithiated nickel oxide and lanthanum-manganese per-ovskite, respectively. Appleby and Foulkes in the Fuel Cell Handbook (101) reviewed the fundamental work as well as the technologically important publications covering electrocatalysis in fuel cells till 1989. 

Once the Ni nanoparticles (NiNPs) are exposed to the alkaline medium, they react instantly to form converted into O-Ni-0 bridge [137], which are involved in electrocatalysis. Nickel phthalocyanine (NiPc) complexes also form O-Ni-O bridges following cyclic voltammetry cycling in basic media. When both NiPc and NiNPs were employed for electrocatalytic oxidation of amitrole, Fig. 36 [137], the oxidation potential on NiNP-GCE was found to be 0.93 V, a value 60 mV which was less positive than that on bare GCE. The NiNP-GCE (Fig. 36e) showed better electrocatalytic activity relative to the NiPc-GCE (Fig. 36d) as judged by the huge catalytic current observed for the former. The NiNP/NiPc-GCE (Fig. 36c) was not... 

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