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In this study, one-pot microwave-assisted synthesis was used to fabricate the graphene (GR)-supported PtCoM catalysts where M = Mn, Ru, and Mo. The catalysts with the molar ratios of metals Pt:Co:Mn, Pt:Co:Ru, and Pt:Co:Mo equal to 1:3:1, 1:2:2, and 7:2:1, respectively, were prepared. Catalysts were characterized using Transmission Electron Microscopy (TEM). The electrocatalytic activity of the GR-supported PtCoMn, PtCoRu, and PtCoMo catalysts was evaluated toward methanol oxidation in an alkaline medium employing cyclic voltammetry and chrono-techniques. The most efficient electrochemical characteristics demonstrated the PtCoMn/GR catalyst with a current density value of 144.5 mA cm−2, which was up to 4.8 times higher than that at the PtCoRu(1:2:2)/GR, PtCoMo(7:2:1)/GR, and bare Pt/GR catalysts.

The performance of direct formic acid fuel cells (DFAFCs) is greatly determined by the catalyst materials. Pt nanoparticles-based heterogeneous structures are among the most important substances for the oxidation of formic acid (FAO). In this study, Ni foam catalyst layered with platinum has been investigated as the catalyst for the oxidation of FAO in acidic and alkaline media. The catalyst has been fabricated via a two-step procedure involving the electroless deposition of the Ni layer using sodium hypophosphite as a reducing agent and subsequent electrodeposition of the platinum layer. In this work, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, and X-ray Diffraction have been used to characterize the morphology, structure, and composition of the prepared catalysts. The electrochemical behavior of the bare Pt, Ni/Ni foam, and PtNi/Ni foam electrodes towards the oxidation of formic acid in acidic and alkaline media was evaluated using cyclic voltammetry. It was found that the PtNi/Ni foam catalyst has a significantly higher electrochemically active surface area of Pt equal to ca. 71 cm2 than pure Pt. Moreover, the PtNi/Ni foam catalyst shows an enhanced electrocatalytic activity towards the FAO via direct pathway in both acidic and alkaline medium compared to those of Ni/Ni and pure Pt electrodes. Furthermore, the prepared PtNi/Ni foam catalyst exhibits greater tolerance of CO than the single-metal Pt in acid solution. Concomitantly, the PtNi/Ni foam catalyst is tolerant to CO poisoning n alkaline media demonstrating high poison removal ability. The PtNi/Ni foam catalyst seems to be a promising future anode material for DFAFCs.

Direct hydrazine fuel cells (DHFCs) are one type of direct liquid fuel cells (DLFCs), where hydrazine is used as a fuel. DHFCs can be operated using a non-precious metal catalyst, which potentially contributes to cost reduction of the hydrazine fuel cell technology. Despite the tremendous progress made in the development of an active catalyst for DHFCs, however, available perfect catalyst able to meet the power output requirements for commercial fuel cell vehicles is still an issue. In this chapter, we summarize the recent advances in the development of catalysts for direct hydrazine fuel cells (DHFCs). The challenges and perspectives in this field are also discussed.

In this study, a platinum-coated Ni foam catalyst (denoted PtNi/Ni foam) was investigated for the oxidation of the formate reaction (FOR) in an alkaline medium. The catalyst was fabricated via a two-step procedure, which involved an electroless deposition of the Ni layer using sodium hypophosphite as a reducing agent and the subsequent electrodeposition of the platinum layer. The PtNi/Ni foam catalyst demonstrated enhanced electrocatalytic activity for the FOR in an alkaline medium compared to the Ni/Ni foam catalyst and pure Pt electrode. Moreover, the PtNi/Ni foam catalyst promoted the FOR at more negative potentials than the Pt electrode. This contributed to a significant negative shift in the onset potential, indicating the high activity of the catalyst. Notably, in alkaline media with the PtNi/Ni foam catalyst, the FOR proceeds via a direct pathway mechanism without significant accumulation of poisonous carbonaceous species on the PtNi/Ni foam catalyst.

The graphene (GR) supported platinum–tungsten (PtW) catalysts with Pt:W molar ratios, equal to 1.6:1, 2.3:1 and 7.1:1, were prepared by a rapid microwave-assisted heating method. The activity of the catalysts was investigated for the electro-oxidation of methanol in an alkaline medium by means of cyclic voltammetry (CV) and chronoamperometry (CA). It has been determined that the rate of methanol oxidation depends on the Pt:W molar ratio in the PtW/GR catalysts. From the CV measurements it follows that the highest current density values, specific and mass activities are obtained for the PtW/GR catalyst with the Pt:W molar ratio equal to 1.6:1. Similarly, the chronoamperometry measurements point to the best performance of the PtW/GR catalyst with the same Pt:W molar ratio. Moreover, in all cases the synthesized PtW/GR catalysts, regardless of different Pt:W molar ratio, show an enhanced electrocatalytic activity towards the direct electro-oxidation of methanol when compared with that for the bare Pt/GR and W/GR catalysts.