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Using electrochemical reduction to convert CO 2 into useful small molecule fuels represents a value-added approach to the simultaneous generation of alternative fuels and environmental remediation of carbon emissions from the continued use of conventional fuels. Here, we report a novel flow cell design for CO 2 electroreduction. The alkaline ion-exchange membranes are used to separate anolyte from aqueous catholyte, and the commercial Sn particles are deposited over a carbon support, which serves as the cathode. Various influence factors on the electrochemical reduction of gaseous CO 2 into fuel are investigated, including a selection of different alkaline-exchange membranes, time duration of the electrolysis, current density and flow rate of electrolyte on the produced formate as a target fuel. Three alkaline membranes (A901, FAD and Yichen) and an acidic membrane (Naffion 117) are used. The maximum Faradaic Efficiencies (FE) of formate formation are 82.8% (Yichen), 79.2% (A901) and 90.1% (FAD), which are comparable to and even higher than that of Nafion 117 membrane (89.2%). In particular, the FAD alkaline membrane showed an applicable prospect with cell voltage of 2.85 V, lower than when using Nafion 117 membrane. We also successfully achieve the formate production rate over 1.47 mmol m −2 s −1 at a working current density of 50 mA cm −2 over 60 min continuous’ operation, allowing the formate concentration up to 1.9 g L −1 . These encouraging results reveal that different ion-exchange membranes have obvious impact on the electrochemical reduction of carbon dioxide (ERC).

In the present study we demonstrate that the activity and selectivity of SnO 2 nanocatalysts during the aqueous-phase electrochemical reduction CO 2 can be effectively tailored by coupling of nanostructured CuO to form SnO 2 CuO nanocomposites. Comparing the Faradaic selectivity of formate as a function of the applied electrode potential and electrolysis time, it is found that CuO incorporation can significantly improve the activity of SnO 2 CuO composite catalysts. When the ratio of CuO in the bulk composite was 50%, the formed SnO 2 (50%)-CuO(50%) nanocomposite gives the best catalytic performance with the onset potential as early as −0.75 V and the current density at −1.25 V as high as about −24 mA cm −2 . Ion chromatography measurement demonstrates that when the electrolysis was held at −1.0 V for 1 h in 0.5 M KHCO 3 , the maximum Faradaic efficiency of formate production can be high up to 74.1%. The outstanding stability of SnO 2 nanocatalyst fabricated electrode is also evidenced due to the stronger synergistic effect induced by CuO compositing, where the SnO 2 (50%)-CuO(50%) composite catalyst keeps a steady current density without any dropt over 30 h’ continuous electrolysis approach. The improved performances are deduced from the strong synergistic interactions between SnO 2 and CuO nanocomposite as evidenced from SEM, XRD and XPS analysis results.

At present, the research on the electrochemical reduction of CO2 (ECR-CO2) mainly focuses on the electrode material and the catalyst. However few studies involved the reactor and reaction conditions. In this study, the commerical available nano-Sn catalyst was coated on a gas diffusion electrode to form a working electrode (Sn/GDE), the influeces of distance between the aonde and the cathode were systematically investigated in a reactor for ECR-CO2. The experiments show that for the electrode distance chnaged from 1.5 cm to 5.7 cm, both current density and Faradaic efficiency were decreased sharply from 34.6 to 10.4 mA cm-2 and 80% to 60%, respectively. However, the distance of 3.3 cm seems to be a critical point, at which the current density was no longer changed.

Due to the extensive use of non-renewable fossil fuels, the crisis in energy is growing, and the gas CO2, which is a product of the burning of hydrocarbons, is contributing to global warming and to acidification of the oceans. Therefore, the issue about carbon dioxide (CO2) capure, sorage and utilization has inspired intensive interests. [2,3] In the various methods of CO2 utilization and recycling, electrochemical reduction of CO2 to transform to useful chemicals or fuels is a potentially efficient way. However, in the procesure of CO2 electroreduction, there is a challenge of the slow kinetic of CO2 electroreduction. [4,5] Overcoming the problems of CO2 reduction under mild conditions would enable solve the energy crisis and the global warming. In the past few decades, researchers found that many metal oxide nanopowders could be the perfect catalysts in the CO2 electroreduction for their controllable various morphologies.[1] In this work, we report the synthesis of SnOx nanocatalysts loaded on the multi-walled carbon nanotubes (MWCNTs), which electrochemical catalyzed CO2 to formate, HCOOH, on the room-temperature with an electrochemical cell having a catalytic SnOx cathode. We controlled different special morphologies by one-step hydrothermal method from SnCl2 precursors. The highest faradaic and energy efficiencies of 65% and 28% were obtained at −1.40 V vs. SCE with particles that were obtained by KOH reduction from a SnCl2 precursor and showed excellent stability in prolonged electrolysis. References [1]C. Zhao, J.L. Wang, J.B. Goodenough Chemical Communication, 52,12175(2016). [2] R. Williams, R.S. Crandall, A. Bloom, Applied Physics Letters, 33,381 (1978). [3] A.S. Agarwal, Y. Zhai, D. Hill, N. Sridhar, ChemSusChem, 4,1301 (2011). [4] M. Gattrell, N. Gupta, A. Co, Energy Conversion and Management, 48,1255 (2007). [5] N. S. Spinner, J. A. Vega and W. E. Mustain, Catalysis Science & Technology, 2,19(2012).

Lead-Acid Battery Technologies: Fundamentals, Materials, and Applications offers a systematic and state-of-the-art overview of the materials, system design, and related issues for the development of lead-acid rechargeable battery technologies. Featuring contributions from leading scientists and engineers in industry and academia, this book:Describe

In this paper, the mechanism and kinetics of oxygen and hydrogen peroxide electrochemical reduction that is catalyzed by an adsorbed cobalt tetramethoxyphenyl porphyrin (CoTMPP) on a graphite electrode were investigated using cyclic voltammetry (CV) and the rotating disk electrode (RDE) technique. The temperature and anion effects on O2 and H2O2 electroreduction processes were also studied. The pH dependencies of cobalt redox centers, and oxygen and hydrogen peroxide reductions were measured for the purpose of exploring the reaction mechanism. In neutral solutions, the oxygen reduction reaction was observed to be a two-electron process, producing H2O2 in the low potential polarization range. In the high potential polarization range, an overall four-electron reduction of O2 to H2O was found to be the dominating process. The kinetic parameters obtained from the RDE experiments indicate that in a neutral solution, the reduction rate at the step from H2O2 to H2O is faster than that seen from O2 to H2O2. Carbon particle-based air cathodes catalyzed by CoTMPP were fabricated for metal-air fuel cell application. The obtained non-noble catalyst content cathodes show considerably improved performance and stability.

Reticulated, open-cell structures based on vitreous carbon substrates electroplated with a Pb–Sn (1 wt.%) alloy were investigated as current collectors for lead–acid batteries. Scanning and backscattered electron microscopy, cyclic voltammetry, anodic polarization and flooded 2 V single-cell battery testing was employed to characterize the performance of the proposed collectors. A battery equipped with pasted electroplated reticulated vitreous carbon (RVC) electrodes of 137 cm 2 geometric area, at the time of manuscript submission, completed 500 cycles and over 1500 h of continuous operation. The cycling involved discharges at 63 A kg PAM −1 corresponding to a nominal 0.75 h rate and a positive active mass (PAM) utilization efficiency of 21%. The charging protocol was composed of two voltage limited (i.e. 2.6 V/cell), constant current steps of 35 and 9.5 A kg PAM −1 , respectively, with a total duration of about 2 h. The charge factor was 1.05–1.15. The observed cycling behavior in conjunction with the versatility of electrodeposition to produce application-dependent optimized lead alloy coating thickness and composition shows promise for the development of lead–acid batteries using electroplated reticulated vitreous carbon collectors.

The use of high specific surface area (>10 cm2 cm−3) reticulated current collectors in lead–acid batteries was studied by cyclic voltammetry, 2 V battery testing and scanning electron microscopy (SEM). Comparative cyclic voltammetry experiments revealed differences in the electrochemical behaviour of reticulated and book-mould current collector designs, with regard to both PbSO4 and PbO2 film formation. Battery testing showed that the electrochemical utilization efficiency of the positive active material (PAM) in flooded cells equipped with about 10 pores cm−1 reticulated collectors was between 30 and 50% higher than for the book-mould grid battery at discharge rates from 5 to 3 h. For instance, at the 3 h rate the PAM utilization efficiency was 45% and the capacity was 101 Ah (kg PAM)−1 for reticulated collectors as opposed to 29.5% and 66 Ah (kg PAM)−1, respectively, for a battery equipped with conventional grids. The results were attributed to differences in PAM morphology as shown by SEM micrographs.

Power Technology Inc. has developed two types of proprietary reticulated, high specific surface area (> 1000 m/sup 2/ m/sup -3/) current collectors for lead-acid batteries manufactured by casting and plating, respectively. The comparative performance of the reticulated and standard grid-type current collectors was studied by single-cell battery testing and scanning electron microscopy (SEM). The electrochemical utilization efficiency of the positive active mass (PAM) in flooded cells equipped with 25 - 30 pores per inch (ppi) reticulated collectors was up to 55% higher than for a grid battery at 3 h discharge rate. These results were attributed to differences in PAM morphology induced by the current collector design, as shown by SEM micrographs. The reticulated battery with Pb-Sn alloy current collectors subjected to daily cycling composed of continuous 19 h float charge at 2.35 V/cell followed by a 5 hour discharge, exhibited a capacity loss of less than 10% in 30 days.