Production of Liquid Solar Fuels and Their Use in Fuel Cells

Abstract

This review focuses on the production of liquid fuels using solar energy combined with their use in direct liquid fuel cells. The production of formic acid, which is the two-electron reduced product of CO 2 , as a solar liquid fuel as well as a hydrogen storage material is discussed together with its use in direct formate fuel cells. Other CO 2 reduction products such as methanol and formaldehyde as solar liquid fuels as well as hydrogen storage materials are reviewed with the performance of the corresponding fuel cells. The production of nitrogen fixation products such as ammonia and hydrazine is also reviewed together with their fuel cells. Finally, the production of hydrogen peroxide from not only pure water but also seawater and dioxygen in the air using solar energy is discussed and combined with the recent development of one-compartment hydrogen peroxide fuel cells.

Photochemical evolution of hydrogen peroxide on lignins

“…4 Aqueous peroxide solutions also store considerable free energy, and therefore peroxide-based energy conversions schemes have been gaining favor as competitors to hydrogen-based approaches. 5,6 In particular, the single-com-partment hydrogen peroxide fuel cell has accelerated peroxide to become a chemical fuel with the attractiveness of ease of handling and storage. 7,8 For all these applications, sustainable peroxide evolution via photocatalysis, [9][10][11] photoelectrocatalysis, 12,13 or direct electrocatalysis 14,15 is of great interest.…”

Single-compartment hydrogen peroxide fuel cells with poly(3,4-ethylenedioxythiophene) cathodes

“…1 Hydrogen peroxide fuel cells are a newer concept which retains the advantage of having a fuel cell with water as a byproduct, but with the significant feature of aqueous hydrogen peroxide as a liquid fuel and the singlecompartment nature where H 2 O 2 is both fuel and oxidizer and thus no separator is necessary. [2][3][4] These fuel cells are part of a broader growing field of energy conversion and storage with H 2 O 2 , driven largely by improvements in photocatalytic platforms for conversion of solar energy into peroxide. [5][6][7][8] In a hydrogen peroxide fuel cell, energy is produced because of the exergonic reactions of oxidation of hydrogen peroxide to produce oxygen and the reduction of hydrogen peroxide to water.…”

CdS Quantum Dots Sensitized 2D La2Ti2O7 Nanosheets as Support for Visible Light‐Assisted Electrocatalytic Methanol Oxidation in Alkaline Medium

“…[3][4][5] Among them, the strategy of coupling Pt with semiconductor nanomaterials as an anode catalyst of DMFCs has been proved to highly enhance the activity and stability compared to the conventional Pt-based catalysts. [1,2,[6][7][8][9][10][11][12][13][14][15][16][17][18][19] The enhanced catalytic behavior of the composite catalysts is first ascribed to the synergistic effect between oxides and Pt, which is similar to the bifunctional mechanism. [20] On the other hand, upon excitation by light, the photogenerated electron-hole pairs of semiconductor nanomaterials may further participate in redox reactions, which enhance the catalytic activity of the Pt-semiconductor catalyst toward methanol oxidation in a photo-assisted fuel cell system.…”