A Sulfite/Air Fuel Cell with Alkali and Sulfuric Acid Byproducts: Bifunctional Electrocatalyst for Sulfite Oxidation and ORR Activity

Abstract

This work attempted to synthesize bifunctional Pd-Pt bimetallic catalysts for a sulfite/air fuel cell via a simple ethylene glycol reduction method. As-prepared Pd-Pt bimetallic catalysts were characterized by transmission electron microscope, X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The diameter of the Pt-Pd bimetals was ∼3–6 nm. The mechanisms of sulfite oxidation and oxygen reduction were investigated. The cell performance was determined to be largely dependent on the sulfite oxidation activity of the catalyst. S(Ⅳ) → S(Ⅵ) is the principal sulfite oxidation reaction for Pd/C, PtPd7.33/C, and PtPd2.75/C, whereas S(Ⅳ) → S(Ⅴ) is the principal reaction for Pt/C, Pt2.18Pd/C, and PtPd1.22/C. PtPd2.75/C is considered a promising bifunctional catalyst for the sulfite/air fuel cell, which exhibits excellent electrochemical activity and long-term stability.

A sulfite/air fuel cell for H2O2 electrosynthesis

“…29 Based on the disc and ring currents, the transferred electron number ( n ) and H 2 O 2 selectivity ( S H 2 O 2 ) involving the ORR can be estimated as follows: 18,32 where N , I d , and I r represent the collection efficiency of the RRDE ( N = 0.37), the disc current, and the ring current, respectively. 12 The corresponding values of n and S H 2 O 2 are depicted in Fig. 3(c) and (d).…”

“…20% Pd/C catalyst was applied as the SO 3 2− oxidation catalyst. 12,19 The anodic catalyst loading of 1.0 ± 0.1 mg cm −2 was loaded onto carbon paper (TORAY, TGP-H-060), which was determined by weight. For the ORR electrode, about a 100 μm carbon sheet containing 70 wt% PTFE was first rolled on a 0.05 mm titanium mesh to prepare a water-repellent layer.…”

“…Inspired by the fuel cell method and our previous work, 12,13 a sulfite/air fuel cell may produce H 2 O 2 without an external electrical energy supply. Herein, we propose a novel strategy for enhancing H 2 O 2 productivity and reducing energy consumption, where the sulfite oxidation reaction is used to replace the oxygen evolution reaction as the anode reaction.…”

Effects of H2O2 Accumulation on the Synthesis Performances of the Sulfite Fuel Cell

“…A homemade Pd/C catalyst was sprayed onto the TGP-H-060 carbon paper to fabricate the sulfite oxidation anode. 22,23 The ORR electrode consisted of a carbon water-repellent layer, a titanium current collector, and an Au 0.5 Pd 0.5 /C catalyst layer. The fabrication of the carbon water-repellent layer has been described in our previous work.…”

Sulfide/Air Fuel Cell for Sulfur Recycling from Sulfide-Containing Wastewater

“…The cell body was fabricated using 5 cm × 5 cm acrylic plates, where the anolyte and air channels were embedded. The homemade Au–Pd/C and Pt/C catalyst inks were sprayed onto a 2 cm × 2 cm carbon paper (TORAY, TGP-H-060) to fabricate the anode and cathode, respectively. , The catalyst inks (5 mg mL –1 ) were prepared by evenly mixing the catalyst and PTFE binder into isopropanol with a weight ratio of 10:1. The catalyst-loading level on carbon paper was 1.0 ± 0.1 mg cm –2 .…”