• Energy Research

In the current research work, palladium (Pd) nanoparticles were electrochemically deposited on a nitrogen doped montmorillonite (CNx-MMT) support using the underpotential deposition (UPD) method. The prepared Pd based composite electrode was studied as an electrocatalyst for methanol fuel oxidation. The catalysts and the supporting materials montmorillonite, acid activated montmorillonite, and nitrogen doped montmorillonite (MMT, HMMT and CNx-HMMT) were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) and electrochemical characterization by cyclic voltammetry (CV). The results indicated that Pd supported on CNx-HMMT possesses enhanced electrocatalytic activity and stability compared to commercial Pd/C, which was attributed to its higher electrochemical surface area (ECSA) (23.00 m2 g−1). The results demonstrated the potential application of novel Pd/CNx-HMMT composite nanomaterial as electrocatalysts for methanol electrooxidation in direct methanol fuel cells (DMFCs).

In recent scientific research, an interest has been gained significantly by rare earth metals such as cerium (Ce), samarium (Sm) and gadolinium (Gd) due to their use in fuel cells as electrolyte and catalysts. When used in an electrolyte, these materials lower the fuel cell's operating temperature compared to a conventional electrolyte, for example, yittria-stabilized zirconia (YSZ) which operates at a high temperature (≥800 °C). In this paper, the tri-doped ceria, M0.2Ce0.8O2-δ(M = Sm0.1Ca0.05Gd0.05) electrolyte powders was synthesized using the co-precipitation method at 80 °C. These dopants were used for CeO2with a total molar ratio of 1 M. Dry-pressed powder technique was used to make fuel cell pellets from the powder and placed them in the furnace to sinter at 700 °C for 60 min. Electrical conductivity of such a pellet in air was 1.2 × 10−2S cm−1at 700 °C measured by the ProboStat-NorECs setup. The crystal structure was determined with the help of X-ray diffraction (XRD), which showed that all the dopants were successfully doped in CeO2. Raman spectroscopy and UV-VIS spectroscopy were also carried out to analyse the molecular vibrations and absorbance, respectively. The maximum open-circuit voltages (OCVs) for hydrogen and ethanol fuelled at 550 °C were observed to be 0.89 V and 0.71 V with power densities 314 mW cm−2and 52.8 mW cm−2, respectively.

A low-temperature solid oxide fuel cell system was developed to use bioethanol and glycerol as fuels directly. This system achieved a maximum power density of 215 mW cm−2 by using glycerol at 580 °C and produced a great impact on sustainable energy and the environment.

Abstract Conventional solid oxide fuel cells (SOFCs) work at high operating temperatures (800–1,000°C). Lowering the operating temperature of SOFCs reduces the open-circuit voltage (OCV) and performance. Herein, a scheme was established to boost the voltage of the developed SOFC using a DC-DC voltage booster. The LTspice technique was used to develop a DC-DC booster, and the code was generated with a minimum of 0.7 V. For experimental evidence, Bi x Ag1.00Fe1−x Zn2O7+δ (BAFZ oxide) materials were synthesized to investigate anodic properties. UV-vis and Fourier transform infrared spectroscopy techniques were used to determine the band gaps and functional groups. The vibrational modes of composite materials were studied via Raman spectroscopy. A slight peak shift toward a higher wavenumber was noted in the BAFZ oxide sample attributed to the addition of bismuth trioxide (Bi2O3). The conductivity was measured and found to be 1.2 S/cm at 600°C in a H2 atmosphere. Fuel cell performance was also measured in the temperature range of 400–620°C, and a maximum OCV of 1.1 V was achieved at 620°C. Finally, the boosted voltage was recorded at 2.2 V under the same circumstances using a DC-DC booster.

Abstract A series of novel poly (2,5-benzimidazole)-grafted montmorillonite (ABPBI-MMT) and sulfonated poly vinyl alcohol (SPVA) composite membranes have been prepared via solution casting method which were further doped with phosphoric acid. The structure of composite membranes has been studied using FTIR, XRD and SEM. The effect of ABPBI-MMT on the water uptake (WU), proton conductivity, mechanical and chemical stability of the resultant membranes has been examined before and after phosphoric acid (PA) doping. This study flaunted that the introduction of ABPBI-MMT into SPVA decreased the WU of pristine polymer matrix as a result of acid-base interaction between the sulfonic acid and benzimidazole groups. However, after PA doping, the WU of the membranes has tremendously boosted. Initially, the influence of ABPBI grafted clay on proton conductivities of SPVA membranes has been studied along with the analysis of PA doping effect on membrane conductivity with fuel cell performance. Furthermore, the proton conductivities of PA doped, and un-doped composite membranes have been studied at high temperatures ranging from 100 to 140 °C under 0% RH. The PA-doped composite membranes show enhanced conductivity values (0.0075 Scm−1) at 140 °C even with 0% RH. The maximum proton conductivity of 0.157 Scm−1 and peak power density of 1100 mWcm−2 have been obtained at 140 °C under 100% RH with 15PBMPP composite membranes. These results indicate that the newly prepared PA-doped PEMs are an excellent candidates for high-temperature PEM fuel cell application.