Biogenic platinum from agricultural wastes extract for improved methanol oxidation reaction in direct methanol fuel cell.

Platinum is the most commonly used catalyst in fuel cell application. However, platinum is very expensive, thus limits the commercialisation of fuel cell system due to the cost factor. This study introduces a biosynthesis platinum from plant extracts that can reduce the cost of platinum production compared to the conventional method and the hazardous during the production of the catalyst. The biogenic platinum was tested on a Direct Methanol Fuel Cell. Advanced biogenic of Pt nano-cluster was synthesized through a novel and facile of one-pot synthesis bio-reduction derived from natural source in the form of plant extracts as reducing agent. Several selected plant extracts drawn from agricultural waste such as banana peel, pineapple peels and sugarcane bagasse extracts were comparatively evaluated on the ability of phytochemical sources of polyphenols rich for the development of single-step synthesis for Pt NPs. Notably, the biogenic Pt NPs from sugar cane bagasse has superior electro-catalytic activity, the enhanced utilization efficiency of Pt and appreciable stability towards methanol oxidation reaction, whose ECSA value approximates 94.58 m2g-1, mass activity/specific activity (398.20 mAmg-1/0.8471 mA/cm2 Pt) which greater than commercial Pt black (158.12 mAmg-1/1.41 mA/cm2 Pt).

Influence of Graphene Oxide on the Ethanol Permeability and Ionic Conductivity of QPVA-Based Membrane in Passive Alkaline Direct Ethanol Fuel Cells.

Passive alkaline-direct ethanol fuel cells (alkaline-DEFCs) appear to be suitable for producing sustainable energy for portable devices. However, ethanol crossover is a major challenge for passive alkaline-DEFC systems. This study investigated the performance of a crosslinked quaternized poly (vinyl alcohol)/graphene oxide (QPVA/GO) composite membrane to reduce ethanol permeability, leading in enhancement of passive alkaline-DEFC performance. The chemical and physical structure, morphology, ethanol uptake and permeability, ion exchange capacity, water uptake, and ionic conductivity of the composite membranes were characterized and measured to evaluate their applicability in fuel cells. The transport properties of the membrane were affected by GO loading, with an optimal loading of 15 wt.% and doped with 1 M of KOH showing the lowest ethanol permeability (1.49 × 10-7 cm2 s-1 and 3.65 × 10-7 cm2 s-1 at 30 °C and 60 °C, respectively) and the highest ionic conductivity (1.74 × 10-2 S cm-1 and 6.24 × 10-2 S cm-1 at 30 °C and 60 °C, respectively). In the passive alkaline-DEFCs, the maximum power density was 9.1 mW cm-2, which is higher than commercial Nafion 117/KOH (7.68 mW cm-2) at 30 °C with a 2 M ethanol + 2 M KOH solution. For the 60 °C, the maximum power density of composite membrane achieved was 11.4 mW cm-2.