Production of hydrogen peroxide as a sustainable solar fuel from water and dioxygen

Abstract

Hydrogen peroxide was produced as a solar fuel from water and dioxygen using solar energy by combination of a water oxidation catalyst and a photocatalyst for two-electron reduction of O 2 in acidic aqueous solutions. Photocatalytic production of H 2 O 2 occurred under photoirradiation of [Ru II (Me 2 phen) 3 ] 2+ (Me 2 phen ¼ 4,7-dimethyl-1,10-phenanthroline) used as a photocatalyst with visible light in the presence of Ir(OH) 3 acting as a water oxidation catalyst in an O 2-saturated H 2 SO 4 aqueous solution. Photoinduced electron transfer from the excited state of [Ru II (Me 2 phen) 3 ] 2+ to O 2 results in the formation of [Ru III (Me 2 phen) 3 ] 3+ and a superoxide radical anion (O 2 _ À) which is protonated to produce H 2 O 2 via disproportionation of HO 2 _ in competition with back electron transfer (BET) from O 2 _ À to [Ru III (Me 2 phen) 3 ] 3+. [Ru III (Me 2 phen) 3 ] 3+ oxidises water with the aid of catalysis of Ir(OH) 3 to produce O 2. The photocatalytic reactivity of H 2 O 2 production was improved by replacing Ir(OH) 3 nanoparticles by [Co III (Cp*)(bpy)(H 2 O)] 2+ in the presence of Sc(NO 3) 3 in water. The optimised quantum yield of the photocatalytic H 2 O 2 production at l ¼ 450 nm was determined using a ferrioxalate actinometer to be 37%. The value of conversion efficiency from solar energy to chemical energy was also determined to be 0.25%. Broader context Photocatalytic production of hydrogen peroxide from earth-abundant water and dioxygen using solar energy as an ideally sustainable solar fuel has remained a great challenge. We report herein for the rst time photocatalytic production of hydrogen peroxide from water and dioxygen under visible light using [Ru II (Me 2 phen) 3 ] 2+ (Me 2 phen ¼ 4,7-dimethyl-1,10-phenanthroline) as a photocatalyst and Ir(OH) 3 nanoparticles or [Co III (Cp*)(bpy)(H 2 O)] 2+ (Cp* ¼ h 5-pentamethylcyclopentadienyl, bpy ¼ 2,2-bipyridine) as a water oxidation catalyst in water containing H 2 SO 4 or Sc(NO 3) 3. A high turnover number and quantum yield have been attained by combining an efficient water oxidation catalyst with a photosensitiser and a Lewis acid in water.

Photocatalytic oxidation of benzene to phenol using dioxygen as an oxygen source and water as an electron source in the presence of a cobalt catalyst

“…23,24 Visible light irradiation of an O 2 -saturated solution of CH 3 CN (MeCN) and H 2 O (v/v = 23 : 2) containing a catalytic amount of 1 (1.0 μM), [Ru II (Me 2 phen) 3 ] 2+ (1.0 mM), Sc(NO 3 ) 3 (100 mM), and benzene (1.0 M) at 298 K resulted in the formation of PhOH [eqn (1)],as shown in Fig. 1.…”

Robust Photocatalytic H2O2 Production by Octahedral Cd3(C3N3S3)2 Coordination Polymer under Visible Light

“…It is also a block building of post-fossil energy framework as a new solar fuel2345. However, the traditional anthraquinone method6, also referred as the indirect process, for H 2 O 2 production is contrary to the concept of the modern green chemistry, because it not only involves the multistep reactions of high energy-consuming hydrogenation and oxidation, but also requires large production plants to minimize capital investment and to obtain highly concentrated H 2 O 2 to reduce transportation costs.…”

Fuel Production from Seawater and Fuel Cells Using Seawater

“…[103] Hydrogenp eroxide (H 2 O 2 )i saclean and sustainable energy source,b ecause the decomposition products are only water and oxygen, and H 2 O 2 is produced from water and dioxygen using solar energy. [104][105][106][107][108][109][110][111][112] H 2 O 2 is superior to H 2 or natural gas, owing to its safe storage and convenient transportation in liquid form. [104][105][106][107][108][109][110][111][112] Furthermore, ao ne-compartment configuration is possible for H 2 O 2 fuel cells, which is structurally much simpler and cheaper than two-compartment hydrogen fuel cells with expensive membranes.…”

“…[104][105][106][107][108][109][110][111][112] H 2 O 2 is superior to H 2 or natural gas, owing to its safe storage and convenient transportation in liquid form. [104][105][106][107][108][109][110][111][112] Furthermore, ao ne-compartment configuration is possible for H 2 O 2 fuel cells, which is structurally much simpler and cheaper than two-compartment hydrogen fuel cells with expensive membranes. [24][25][26]113] Efficient photocatalytic production of H 2 O 2 from seawater and O 2 in the air was performed in at wo-compartment photoelectrochemical cell, composed of mesoporous WO 3 supported on af luorine doped tin oxide (FTO) glass substrate (m-WO 3 / FTO) as ap hotocatalyst for H 2 Oo xidation and ac obalt chlorin complexs upported on ac arbon paper ([Co II (Ch)]/CP) as an electrocatalyst for the selectivet wo-electron reduction of O 2 , [114,115] as shown in Figure 12.…”