Bismuth(III) and Copper(II) Oxides as Catalysts for the Electro‐Oxidation of Organic Compounds

Abstract

It was shown that copper(II) oxide bound to the anode with polystyrene containing a cationic surfactant acted as a catalyst for the oxidation of organic compounds in aqueous systems in a manner similar to powdered copper oxide suspended in aqueous systems containing the organic compounds and the cationic surfactant. Voltammetric measurements made with these electrodes were reproducible over an extended period of time, and it was possible to reproducibly use the polystyrene bound copper oxide as a catalyst for anodic destruction of several organic compounds. On the other hand, while bismuth(III) oxide (Bi203) bound to platinum with polystyrene was a catalyst for the oxidation of organic compounds in cationic surfactant suspensions, the results were not reproducible. The rate of renewal of the reactant adsorbed on the anode after oxidation was extremely slow. In addition, the Bi203 gradually changed during the catalytic reaction to BiO(OH). Both of the bismuth compounds acted as catalysts for the oxidation reaction, but the potential for oxidation of Bi203 was less anodic than the potential for BiO(OH). Previous coulometric experiments have indicated clearly that the catalytic intermediate for the copper oxidations is copper(III); however, the coulometric oxidations of bismuth indicate that the intermediate has a bismuth oxidation state slightly over 4. Most probably the intermediate is bismuth (V) and some of the bismuth had agglomerated so that not all of it has been oxidized.

Regulation of Catalyst Immediate Environment Enables Acidic Electrochemical Benzyl Alcohol Oxidation to Benzaldehyde

“…Previously, Bi was used as an electrocatalyst for the oxidation of organic molecules. 24,25 including BnOH, albeit to moderate selectivities. 26−32 However, selective oxidation of BnOH to the desired product remains challenging.…”

“…In this report, as a model system, we chose to study BnOH electro-oxidation using a bismuth (Bi) electrocatalyst in an acidic medium. Previously, Bi was used as an electrocatalyst for the oxidation of organic molecules. , Moreover, Bi/bihydroxide was used as a promotor alongside additional metal (M = Pt abd Pd) (MBi x ) oxidation of different alcohols including BnOH, albeit to moderate selectivities. − However, selective oxidation of BnOH to the desired product remains challenging. Hence, to test our approach, we have coated a Bi-based electrocatalyst with a thin layer of Zr 6 -oxo-based MOF, UiO-66 .…”

“…Previously, Bi was used as an electrocatalyst for the oxidation of organic molecules. 24 , 25 Moreover, Bi/bihydroxide was used as a promotor alongside additional metal (M = Pt abd Pd) (MBi x ) oxidation of different alcohols including BnOH, albeit to moderate selectivities. 26 − 32 However, selective oxidation of BnOH to the desired product remains challenging.…”