Johnson Matthey Hydrogen Technologies Limited

Johnson Matthey Fuel Cells Limited

Gm Global Technolgoy Operations, Inc.

Alejandro Martinez Bonastre

Geoffrey Hugh Spikes

Rachel Louise O'Malley

Geoffrey Spikes

Jonathan David Brereton Sharman

Jonathan Sharman

Daniel Marin Florido

Adam Hodgkinson

Frederick Tadeusz Wagner

Rachel Louise O'malley

The present invention provides a method of preparing an electrocatalyst ink, the method comprising a step of contacting a dispersion with a separation material.

Electrocatalyst ink

The present invention provides a method of preparing an electrocatalyst ink, the method comprising a step of contacting a dispersion with a base metal-binding agent.

The present invention provides a method of preparing a catalyst material, said catalyst material comprising a support material and an electrocatalyst dispersed on the support material: said method comprising the steps: i) providing a support material; then ii) 10 depositing a silicon oxide precursor on the support material; then iii) carrying out a heat treatment step to convert the silicon oxide precursor to silicon oxide; then iv) depositing said electrocatalyst or a precursor of said electrocatalyst on the support material; then v) removal of at least some of the silicon oxide.

Catalyst preparation

The use of an electrocatalyst material in an anode catalyst layer, wherein the electrocatalyst material comprises a support material, the support material comprising a plurality of individual support particles or aggregates wherein each individual support particle or aggregate has dispersed thereon (i) first particles and (ii) second particles, wherein: (i) the first particles comprise Pt optionally alloyed with an alloying metal X1; wherein the optional alloying metal X1 is selected from the group consisting of Rh, Ti, Os, V, Co, Ni, Ga, Hf, Sn, Ir, Pd, Mo, Zn, W, Zr and Re; (ii) the second particles consist essentially of a second metal or a second metal compound wherein the second metal is selected from the group consisting of Ir and Ru and the second metal compound comprises IrX2 wherein X2 is selected from the group consisting of Ta, Nb, Ru, Ni and Co; and wherein if the first particles consist of Pt then the second particles do not comprise IrTa; and wherein if the first particles consist of Pt without alloying metal X1 and the second particles consist essentially of a second metal which is Ir, each individual support particle or aggregate of the support material of the electrocatalyst material has dispersed thereon only the said first and second particles; or wherein each individual support particle or aggregate has dispersed thereon (i) first particles and (ii) third particles, wherein: (iii) the third particles comprise Au or a third metal alloy; wherein the third metal alloy is selected from the group consisting of AuX3 and PdX4, wherein X3 is selected from the group consisting of Pt, Pd, Cu, Ir and Sn; and X4 is selected from the group consisting of Hg, Au, Sn, Co, Ni, Ga, In, Zn, W and Pb.

Catalyst

A process for preparing a catalyst material, said catalyst material comprising a support material, a first metal and one or more second metals, wherein the first metal and the second metal(s) are alloyed and wherein the first metal is a platinum group metal and the second metal(s) is selected from the group of transition metals and tin provided the second metal(s) is different to the first metal is disclosed. The process comprises depositing a silicon oxide before or after deposition of the second metal(s), alloying the first and second metals and subsequently removing silicon oxide. A catalyst material prepared by this process is also disclosed.

An electrocatalyst material comprising: (i) a support material comprising a plurality of individual support particles or aggregates; (ii) first particles comprising a first metal and an alloying metal; and (iii) second particles consisting of a second metal or a second metal oxide, wherein the second metal is platinum or iridium; wherein each individual support particle or aggregate has dispersed thereon first particles and second particles, characterised in that the mean average particle size of the second particles is smaller than the mean average particle size of the first particles is disclosed. The electrocatalyst material has particular use in an electrode, such as the cathode, of an electrochemical cell, such as a fuel cell.

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Reading, United Kingdom

Alejandro Martinez Bonastre