Co-existence of Pd, Bi2O3 and CuO supported on porous activated biocarbon for electrochemical conversion and energy storage

The co-existence of metal oxides (MO) and activated carbon (AC) causes changes in the catalytic behaviour and activity which would contribute greatly to a number of applications. Pd-AC/Bi2O3/CuO synthesized via the green process was used as a catalyst for electro-oxidation of ethanol and energy storage. Carbonization at 800 degrees C and hydrothermal treatment in a microwave oven yielded biocarbon (BC) from banana peels with mesoporous and high surface area (690.42 m(2) g(-1)). Cyclic voltammetry (CV), galvanostatic charge-discharge, electrochemical impedance spectroscopy, and chronoamperometry were used to assess the electroactivity of the catalyst (CA). CV of Pd-AC/Bi2O3/CuO revealed 40% enhanced current densities (j) in ethanol electro-oxidation compared to that of the prepared Pd/AC, while the j determined at 20 min of CA measurements was 60% higher than those of the other prepared catalysts. Among the other catalysts, Pd-AC/Bi2O3/CuO revealed high capacitive j and confirmed the near ideal capacitive behaviour with good electrochemical reversibility while the calculated C-sp of the electrode system was found to be 369.1 F g(-1) at 0.95 mA cm(-2). The calculated time constant (tau(0)) value for Pd-AC/Bi2O3/CuO was higher, 390 ms, implying that the catalyst performs better with quick delivery of stored charges indicating better energy delivery capability.

Automated summary

The combination of metal oxides and activated carbon in Pd-AC/Bi2O3/CuO catalyst shows enhanced catalytic behavior and activity for ethanol electro-oxidation and energy storage. The catalyst exhibits high current densities, capacitive j, good electrochemical reversibility, and quick delivery of stored charges, indicating superior energy delivery capability.