Selectivity Control of Oxygen Reduction Reaction over Mesoporous Transition Metal Oxide Catalysts for Electrified Purification Technologies

• Direct electrification of oxygen-associated reactionscontributesto large-scale electrical storage and the launch of the green hydrogeneconomy. The design of the involved catalysts can mitigate the electricalenergy losses and improve the control of the reaction products. Weevaluate the effect of the interface composition of electrocatalystson the efficiency and productivity of the oxygen reduction reaction(ORR) and oxygen evolution reaction (OER), both mechanistically andat device levels. The ORR and OER were benchmarked on mesoporous nickel-(II)oxide and nickel cobaltite (NiO and NiCo2O4,respectively) obtained by a facile template-free hydrothermal synthesis.Physicochemical characterization showed that both NiO and NiCo2O4 are mesoporous and have a cubic crystal structurewith abundant surface hydroxyl species. NiCo2O4 showed higher electrocatalytic activity in OER and selectivity towater as the terminal product of ORR. On the contrary, ORR over NiOyielded hydroxyl radicals as products of a Fenton-like reaction ofH(2)O(2). The product selectivity in ORR was usedto construct two electrolyzers for electrified purification of oxygenand generation of hydroxyl radicals.

Ämnesord

NATURVETENSKAP  -- Kemi -- Annan kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Other Chemistry Topics (hsv//eng)

Nyckelord

oxygen reduction reaction; oxygen evolution reaction; oxygen on demand; mesoporous oxides; nickel(II)oxide; nickel cobaltite; hydroxyl radical

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