Bridge to Fuel Cell Molecular Catalysis: 3D Non-Platinum Group Metal Catalyst in MEAs

Abstract

Transition metal porphyrin complexes have been mounted in a three dimensional homogenous distribution inside the ionomer of catalyst layers in MEAs to achieve competitive fuel cell catalysis activity. The effect of electrode components including ionomer, carbon, catalyst, and mediator, and ionomer film thickness, is investigated in fuel cell molecular catalysis system. Membrane electrode assembly (MEA) durability testing has been conducted. SEM and TEM techniques are employed to investigate molecular catalysis electrode micro- and nano- structure and morphology. To date, surprisingly, the best fuel cell performance, i.e. 1280 mA/cm2 of maximum/short-circuit current density is achieved, approaching that of Pt-based electrode, indicating higher turnover frequencies than Pt although with poorer voltages.

Organometallic Polymer Electrolyte Membrane Fuel Cell Bis‐Ligand Nickel(Ii) Complex of 1,5‐Di‐P‐Tolyl‐3,7‐Dipyridine‐1,5,3,7‐Diazadiphosphacyclo‐Octane Catalyst

“…Recently, a series of papers has been published, in which a biomimetic approach has been applied to the creation of organometallic complexes used for oxygen reduction reaction (ORR) in a FC membrane electrode assembly (MEA). The aqua complex Ni II Ru II , [Ni II LRu II (H 2 O)(η 6 ‐C 6 Me 6 )](NO 3 ) 2 has been used as a catalyst for both HOR and ORR ([1](NO 3 ) 2 , where L= N , N ′‐dimethyl‐ N , N ′‐bis(2‐mercaptoethyl)‐1,3‐propanediol‐amine); and the MEA has been tested directly in the fuel cell.…”

“…Recently,aseries of papersh as been published, [6][7][8][9] in which ab iomimetic approachh as been applied to the creation of organometallic complexes used for oxygenr eduction reaction (ORR) in aF Cm embranee lectrode assembly (MEA).T he aqua complex Ni II Ru II ,[ Ni II LRu II (H 2 O)(h 6 -C 6 Me 6 )](NO 3 ) 2 has been used [7] as ac atalyst for both HOR and ORR ( [1](NO 3 ) 2 ,w here L = N,N'-dimethyl-N,N'-bis(2mercaptoethyl)-1,3-propanediol-amine);a nd the MEA has been tested directly in the fuel cell. Theo pen-circuit voltage (OCV) was 0.29 Va nd the maximum power density was 11 mWcm À2 .T hen, the authors have shown that the useo f peroxoc omplex [Ni II Ru IV ]l eads to an increase in the performanceo ft he FCs.T he OCV was increased to 0.42 V, and the power density reached the value of 26 mWcm À2 .…”

Cyclic voltammetry of fast conducting electrocatalytic films

“…[10][11][12][13][14][15][16] In this framework, we expect the kinetic behavior of the film to be jointly governed by the catalytic reaction and the substrate diffusion inside the film as represented in Fig. It includes the case where charge transport proceeds through rapid electron hopping.…”

Effects of Redox Mediators on the Catalytic Activity of Iron Porphyrins towards Oxygen Reduction in Acidic Media

“…With these advances, the site density can be increased to levels that support high current densities. One approach is to build a 3D, molecular polymer redox layer on the electrode surfaces 5. The polymer redox layer includes a molecular catalyst, and this structure results in full access to all species (electrons, protons, and substrates) with increased reaction rates.…”

“…The polymer redox layer includes a molecular catalyst, and this structure results in full access to all species (electrons, protons, and substrates) with increased reaction rates. In our previous studies,1, 5, 6 we proposed a polymer redox film having a non‐noble‐metal complex impregnated with Nafion as a new cathode catalyst layer for PEMFCs. In particular, a non‐noble‐metal catalyst (metal porphyrins) binds with the sulfonic acid sites of Nafion to form a 3D molecular catalyst, and the polymer redox film is attached to the electrode surface.…”