Phosphotungstic acid

About: Phosphotungstic acid is a research topic. Over the lifetime, 1925 publications have been published within this topic receiving 38059 citations. The topic is also known as: Phosphowolframic acid.

Promoting Electrochemical Performance of Fuel Cells by Heteropolyacid Incorporated Three-Dimensional Ordered Nafion Electrolyte

Abstract: A novel three-dimensional (3D) Cs 2.5 H 0.5 PW 12 O 40 -Nafion electrolyte materials are designed by impregnatingCs 2.5 H 0.5 PW 12 O 40 ( m phosphotungstic acid : m Cesium carbonate =50:7) into the 3D ordered Nafion matrixes, which are synthe-sized by monodisperse poly(methyl methacrylate) (PMMA) colloidal crystal template with subsequent removalof the organic template by solvent extraction. The results show that the reconstruction of the Nafion elec-trolyte to a 3D well-organized porous matrix form highly ordered proton transportation pathway, resulting inthe improvement of the proton conductivity at high temperature and the Cs 2.5 H 0.5 PW 12 O 40 proton carriers in thechannels also play an assistant role in enhancing the proton conductivity. Furthermore, the spillover effect of theCs 2.5 H 0.5 PW 12 O 40 proton carriers effectively increases the electrochemical activity of the membrane electrode,lowers the interface impedance and improves the fuel cell performance.KEYWORDS: PEM Fuel Cell, Proton Exchange Membrane, 3D Ordered Nafion Matrix, Cs

Sulphonated poly ether ether ketone/ polyvinyl alcohol/phosphotungstic acid composite membranes for pem fuel cells *

Abstract: Composite membranes with polyvinyl alcohol (PVA), sulphonated poly ether ether ketone (SPEEK) and phosphotungstic acid (PWA) were prepared using solvent casting method. The proton conductivities of such membranes were found to be in the order of 10–3S/cm in the fully hydrated condition at room temperature as measured by impedance spectroscopy. The crystalline properties were studied by X-ray diffraction analysis. The thermal properties were determined by TGA and DSC techniques. The tensile strength and percentage elongation were obtained from UTM studies. Water and methanol uptake of these membranes were studied.

Lithium/bismuth co-functionalized phosphotungstic acid catalyst for promoting dinitrogen electroreduction with high Faradaic efficiency

Abstract: Summary Ammonia occupies a significant standing in the global economy. As a promising alternative to the energy-intensive Haber-Bosch process, electrochemical nitrogen reduction could achieve sustainable ammonia synthesis. However, the attractive alternative suffers from the bottleneck of insufficient activity and low electron selectivity. Here, we report an efficient electrocatalyst using phosphotungstic acid as platforms to anchor bismuth species on the 4-fold hollow site and anchor lithium species on the 3-fold hollow site, which reaches high ammonia yield rates of 61 ± 1 μg h−1 mgcat.−1 and Faradaic efficiencies of 85% ± 2% at −0.1 V versus reversible hydrogen electrode (RHE). Experiments and theoretical calculations reveal that the Biδ+ species can promote the activation and hydrogenation of nitrogen at adjacent unsaturated tungsten active sites, and the incorporated lithium species reduce the hydrogen reduction rate in undesired water splitting. This synergistic functionalization of bismuth and lithium species contributes to the high-efficient catalyst.