# Progress in the Development of Electrodeposited Catalysts for Direct Liquid Fuel Cell Applications
## 4 Shape Control--A Way Forward
Another facile approach is to reduce the as synthesized GO on carbon cloth electrode (CCE), commercially available support (also known as GDL) used in fuel cells, followed by its potentiostatic reduction, and synthesise Pt using electrodeposition. The advantages of this approach are, it is a facile, economic, large scale, and eco-friendly method. It involves a single step reduction process that forms a thin and flexible structure with more wrinkles on the CCE, which may provide more perfect sites for the deposition of noble metal nanoparticles. [PERSON] et al. [87] developed this approach to synthesise Pt nanoflowerson reduced graphene oxide (RGO)/CCE by potentiostatic electrodeposition. Firstly, an aqueous solution of GO was coated on the CCE, followed by single step potentiostatic reduction of GO. Then the deposition was carried out on the RGO/CCE substrate using 3 mM H\({}_{2}\)PtCl\({}_{6}\) in 0.5 M H\({}_{2}\)SO\({}_{4}\) for Pt nanoflowers and 3 mM H\({}_{2}\)PtCl\({}_{6}\) in 0.1 M KCl for Pt nanoparticles. For comparison, deposition was carried out on bare CCE without RGO. X-ray photoelectron spectroscopy (XPS) results showed a dominant increase in C=C surface functional groups and declined oxygenated groups on reducing GO. SEM images showed the formation of wrinkles, confirming the presence of RGO. Pt/CCE and Pt/RGO/CCE displayed a flower-like morphology when deposited in an acidic medium. On the other hand, they displayed spherical morphology when deposited in an alkaline medium. In both cases, Pt/RGO/CCE showed better dispersion and uniformity. Electrochemical studies showed that Pt catalysts deposited on RGO/CCE exhibit higher electrochemical surface areas and electro-catalytic activities towards the oxidation of methanol, formic acid with improved stability than that of the Pt catalysts deposited on bare CCE. The reason for their enhancement in activities is due to the well dispersion of Pt on RGO/CCE and easier organic molecule penetration through its surface. [PERSON] et al. [88] studied the activity of facet-dependent bimetallic CoPt\({}_{3}\) catalysts for the oxidation of methanol. In order to create shape-controlled nanoparticles, growth was regulated, while controlling the nucleation. During the nucleation stage, an excessive amount of precursor is typically consumed, hampering the further growth of the metal alloy (CoPt\({}_{3}\)). To circumvent this, a non-injection method was employed to synthesise spherical, cubical, and flower-like nanocrystals with selective facets by injecting the precursors into the reaction mixture under hot temperature condition for rapid nucleation with slow crystal growth. By altering the oleylamine (OLA) to oleic acid (OA) ratio in the presence of benzyl ether, a non-coordination solvent, the nucleation and growth rates were partially adjusted. Physical characterization results revealed that the cubic crystals exhibited smaller sizes with {100} dominant faces while the flower-like crystals resulted in larger size with {111} face as the predominant ones. Comparison of the electrochemical test results demonstrated the dual role played by flower-like crystals in facilitating the CO removal and improving the electrooxidation of methanol. Recent advances in the development of technologies for controlled synthesis of materials at the nanoscale have opened up new avenues for designing catalysts atom by atom. The complexity lies in determining how the engineering of a surface's structure should be directed toward desired catalytic functionality [89]. Engineering noble metals into porous nanoparticles (NPs) is considered to be an excellent way of enhancing catalytic performance through the generation of more active high index facets [90]. Shape controlled noble metal (Pt, Pd) nanocrystals enclosed by high index facets are known to primarily impact the unexceptional activity and stability enhancement towards reactions such as organic molecule oxidations, ORR, etc. However, it is challenging to synthesize the high index faceted nanocrystals owing to their high surface energy.