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Nano sized copper oxide-zirconia particles were prepared by using a sol-gel technique. The phase change with the calcinations temperature was also investigated for the sample containing 30 wt% copper. It was found that the calcinations temperature strongly influenced the interaction between the active species and support and hence the structure and catalytic performance. Low calcinations temperature yielded poorly crystallized catalysts and favored the formation of a Cu(OH)₂ and Zr(OH)₄ like structure. The results show that cubic ZrO₂ and copper oxide were present below calcinations at 400°C, and cubic ZrO₂ with some amount of monoclinic ZrO₂ and tetragonal ZrO₂, as well as copper oxide, formed after calcinations at 500°C. However, below heating at 500°C, amorphous compounds were obtained; suggesting that 500°C could be a phase transition point. The incorporation of copper in the ZrO₂ lattice resulted in a loss of order in the ZrO₂ structure when calcined at 500°C, with a further increase in the calcinations temperature leading to the phase change. In this work, the latest results on nano crystalline CuO-ZrO₂ as the catalyst for hydrogen synthesis from methanol is reported. The effect of calcinations temperature on the nanoparticle structure of catalyst is focused.

Although biomass-derived metal-free electrocatalysts for oxygen reduction reaction (ORR) have garnered increasing attention, their ORR performance is lower than that of commercial 20% Pt/C. To improve their ORR performance, a series of porous carbons with high $N$ contents are prepared by pyrolyzing a mixture of spinach leaf powder and urea at different mass ratios (1:0, 1:5, 1:10, and 1:15) at a high temperature; the resultant materials are labeled as S-850, S-850-5, S-850-10, and S-850-15, respectively. The results indicate that the $N$ contents in the as-synthesized S-850, S-850-5, S-850-10, and S-850-15 products are 5.43, 5.74, 5.93, and 5.93 at%, respectively, which gradually increase with increasing urea contents, while the $P$ and $S$ contents (0.7 and 0.3 at%, respectively) show no change. Among all the as-synthesized products, the sample obtained by the addition of 10 wt.% urea (S-850-10) exhibits the best ORR catalytic performance in an O₂-saturated 0.1 M KOH solution with a half-potential of 0.748 V and a diffusion-limited current density of −4.76 mA cm${}^{-2}$ at 0.4 V. The half-potential and diffusion-limited current density of S-850-10 are improved by 0.53% and 8.61% compared to those of S-850 (0.744 V and −4.35 mA cm${}^{-2}$ at 0.4 V, respectively). These findings indicate that urea can be used as an $N$ resource to increase the $N$ content of biomass-derived metal-free porous carbon, enhancing its ORR performance.

In this paper we report the electrochemical behavior of heat-treated carbon blacks and Pt/C catalysts. Cyclic voltammetry indicates that the heat-treated carbon black as catalyst support does not improve the Pt/C catalyst's activity for methanol oxidation. An XPS study of a Pt-loaded carbon black indicates that the amounts of oxidized platinum and oxygen-functional groups on catalysts are decreased when the platinum particles are deposited on the heat-treated carbon surface. These changes in the surface and crystalline structural properties of carbon materials lead to the catalytic activity change in methanol electro-oxidation.

The cuprous oxide nanoparticles were prepared with glucose as reducing agent by a wet-chemical method. The composition and structure of the catalysts were characterized with XRD and SEM analysis. The catalytic activity and stability of the catalyst for the H₂O₂ reduction were studied using the curves of cyclic voltammetry and chronoamperometry. The results showed that the crystal structure of the synthesized Cu₂O was the pure cubic phase and the crystallite size was about 19.5 nm. The Cu₂O powder was spherical and the average diameter of the spheres is about 1.0 μm. The Cu₂O nanoparticles were active for H₂O₂ electroreduction and the current density was about 30 mA cm^-2 at E = -0.4 V.

A variety of modification approaches such as cross-linking and nano blending have been explored to prepare efficient membranes based on Sulfonated polyether ether ketone (SPEEK). The addition filler is also one of the most widely used approaches to modify the SPEEK. The crosslinked membranes were utilized as proton exchange membranes (PEM) for fuel cell application. The performances of these composite membranes were comparative researched in terms of water uptake, ion exchange capacity, proton conductivity, and methanol permeability.While the nanohybrid membranes display remarkably enhanced proton conduction property due to the incorporation of additional sites for proton transport and the formation of well-connected channels by bridging the hydrophilic domains in SPEEK matrix. The as-prepared nanohybrid membranes also show elevated thermal and mechanical stabilities as well as decreased methanol permeability.

The work presents the synthesis and characterization of amidated pectin (AP) based polymer electrolyte membranes (PEM) crosslinked with glutaraldehyde (GA). The prepared membranes are characterized by Fourier transform infrared spectroscopy (FTIR), organic elemental analysis, X-ray diffraction studies (XRD), thermogravimetric analysis (TGA) and impedance spectroscopy. Mechanical properties of the membranes are evaluated by tensile tests. The degree of amidation (DA), molar and mass reaction yields (Y_M and Y_N) are calculated based on the results of organic elemental analysis. FTIR spectroscopy indicated the presence of primary and secondary amide absorption bands. XRD pattern of membranes clearly indicates that there is a considerable increase in crystallinity as compared to parent pectin. TGA studies indicate that AP is less thermally stable than reference pectin. A maximum room temperature conductivity of 1.098 × 10^-3Scm^-1 is obtained in the membrane, which is designated as AP-3. These properties make them good candidates for low cost biopolymer electrolyte membranes for fuel cell applications.

A hierarchical carbon material containing nanopores (micropores and mesopores) and micrometric sized capillaries (macropores) is produced using a combination of hard and soft templates. The hard template is a polypropylene (PP) cloth which decomposes during pyrolysis leaving a macroporous structure. The soft template is a cationic polyelectrolyte which stabilizes the resorcinol/formaldehyde (RF) resin porous structure during drying to give a nanoporous RF resin. The method produces a nanocomposite of the porous RF resin with an imbibed PP cloth. The composite is then pyrolyzed in a inert gas atmosphere to render a carbon material having macropores as well as micro/mesopores. The material exhibits both a large surface area (S_BET = 742 ± 2 m²/g) due to nanopores and goof fluid permeability due to micrometric sized pores. The macropores can be oriented during fabrication. The nanoporous surface can be used to support metal nanoparticles for fuel cell while the macropores allow easy flux of gas and liquids through the monolithic material.

In this work, slurry spraying is evaluated as a deposition method of thin electrolytes for solid oxide fuel cells. This method is cost effective, uncomplicated and have several advantages in respect to widely used screen printing method. Influence of deposition parameters: slurry concentration, spraying pressure are discussed. Anode supported cells are produced with three different electrolyte thicknesses: 5, 10 and 20 μm showing flexibility of the developed method. Prepared fuel cells achieve satisfactory power densities of almost 1 W cm^-2 at 800°C. As evidenced by impedance spectroscopy, performance of cells is determined by the polarization resistance. Cross sections of cells show that all electrolyte layers are of high quality. Slurry spraying is a feasible method for fabrication of functional cells and can be easily scaled for large quantity production.

Catalysts are a key component of polymer electrolyte membrane fuel cells (PEMFCs). In this work, nitrogen-doped three-dimensional graphene-supported platinum (Pt-3DNG) catalysts are successfully prepared and characterized. SEM and TEM images show the Pt nanoparticles are uniformly dispersed in the sheets of nitrogen-doped 3DNG. Compared with that of the commercial Pt/C catalysts, Pt-3DNG show much better oxygen reduction reaction (ORR) activity and cycling stability, and the reduction in limit current density after 1000 cycles is only about 1.6% for the Pt-3DNG catalysts, whereas 7.2% for the commercial Pt/C catalysts. The single cell using Pt-3DNG catalysts in both the anode and the cathode show a higher peak power density (21.47mW cm${}^{-2})$ than that using commercial Pt/C catalysts (20.17mW cm${}^{-2})$ under the same conditions. These properties make this type of catalyst suitable for the application in PEMFCs.

In order to develop non-noble metal-based electrocatalysts for glucose oxidation, the Ni-doped, urchin-like Bi₂S₃ particles were prepared by a solvothermal method using the solvent of ethylene glycol/H₂O. The obtained products were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The background signal from capacitance current is relatively low and the electrocatalytic oxidation current of glucose relatively high due to the urchin-like nanostructure of Bi₂S₃ particles and high surface area where the presence of Bi also improves the electrocatalytic performance of Ni${}^{II}$/Ni${}^{III}$ shift.

Environmentally responsible and minimal natural variation in electric power generation has been a goal of researchers for several decades. With the establishment of the electrical power generation potential from microalgae’s photosynthesis, several researchers revealed interesting microbial fuel cell configurations to improve the output of electrical parameters. However, little work is done to understand the electrical charge collected from photosynthesis. This article proposes a fuel cell-based electrochemical modeling of the micro-photosynthetic power cell. The model is developed, excluding significant analytical assumptions at stationary conditions. Due to the complexity of modeling the electron release from photosynthesis, the electron release reactions are substituted with a simpler redox coupler of similar electric potential to that of photosynthesis. The micro-photosynthetic power cell revealed that the electron collection rate does not directly correlate to the photosynthesis electron chain. It might remain constant for a specific electrical load. The peak power is obtained at a different operating loading than the internal resistance of the device. The experimental open circuit voltage ($\sim$0.96V) and the peak power ($\sim$0.18mW) are predicted accurately by this modeling approach. The results show that the fill factor remains constant with respect to several effective electrode surface areas. Based on this theoretical modeling, we believe that with optimized algal physiological state and micro-photosynthetic power cell’s effective surface area, this micro-photosynthetic power cell will be useful for application in low-power applications.