Electrocatalytic H2 Oxidation Reaction

Abstract

Hydrogen (H 2 ), an important material and product in chemical industries, has been investigated as a new clean energy source for many decades [1][2][3]. With the rapid development of proton exchange membrane (PEM) fuel cell technology, in which H 2 is used as a fuel, the chemical energy stored in this H 2 can be electrochemically converted to electric energy with zero emissions and high efficiency. The dream of a hydrogen economy era therefore seems closer to reality. Beginning in the 1990s, the advantages of PEM fuel cells, including zero/low emissions, high energy efficiency, and high power density, have attracted world-wide research and development in several important application areas, including automotive engines, stationary power generation stations, and portable power devices [4]. With successful demonstrations of fuel cell technology, in particular in automotive applications, commercialization of this technology has become a strong driving force for further development in the critical areas of cost reduction and durability. The major cost of a PEM fuel cell is the platinum (Pt)-based catalysts. At our current technological stage, these Pt-based catalysts for both the cathodic O 2 reduction reaction (ORR) and the anodic H 2 oxidation reaction (HOR) are the most practical catalysts in terms of catalytic activity and lifetime stability. Therefore, research and development to improve catalytic activity and stability has shot to the fore in recent years. Although both theoretical and experimental approaches have resulted in great progress in fuel cell catalysis [2,3,5,6], continuous effort is necessary to develop breakthrough fuel cell catalysts that are cost-effective and highly durable for commercial use.With respect to fuel cell catalysis, most research has been focused on cathode ORR catalysts development, because the ORR kinetics are much slower than the anodic HOR kinetics; in other words, the fuel cell voltage drop polarized by load is due mainly to the cathode ORR overpotential [7,8]. However, in some cases the overpotential of the anodic HOR can also contribute a non-negligible portion of the overall fuel cell voltage drop [8]. Therefore, the catalytic HOR on the fuel cell anode catalyst is also worth examining.

Measuring individual overpotentials in an operating solid-oxide electrochemical cell

“…Other contributions might include differences in the micro-structural quality of the electrodes and the accumulation of impurities at the TPB. While the performance difference between Ni and Pt is not at all surprising 31,32 , we emphasize the directness of our approach to make such determinations.…”

Understanding the Role of Ir during Methanol Oxidation at PtxIryAlloy Nanoparticles

“…5 shows that the CO stripping peaks for Pt/VC and Ir/VC are centered at 0.83 and 0.93 V vs. RHE, respectively. Ir is known to adsorb hydroxide ions and form an oxide film at more negative potentials than Pt 41 and hence CO oxidation/removal (facilitated by nearby OH (ads) groups) should also take place at more negative potentials at Ir than at Pt. However, Fig.…”

Improving the electrocatalytic activity for formic acid oxidation of bimetallic Ir–Zn nanoparticles decorated on graphene nanoplatelets

“…where Q H (C) is the charge transfer from the catalyst in the H 2 adsorption region, q h (μC cm −2 ) is the charge transfer for the monolayer H 2 adsorption on the Ir surface, and m (g) is the catalyst loading on the electrode. The calculation of Q H involves the integration of area under H 2 adsorption peak, whereas q h is the constant value from reference 220 μC cm −2 [30]. As shown in table 2, the highest value of ECSA was of the Ir/GNP catalyst, whereas Ir-Zn/GNP catalysts showed decreased values.…”