The present invention relates to a method of preparing a catalyst article comprising steps: (a) preparing a washcoat composition by combining at least the following components: a support material comprising a mixed oxide, a mixture of oxides or a molecular sieve comprising (i) alumina and (ii) silica and/or zirconia; a metal oxide sol comprising at least one of titania, silica or zirconia; a liquid medium; (b) applying the washcoat composition to a substrate to form a washcoating; and (c) drying and/or calcining the washcoating; wherein the method further comprises a step of impregnating the support material with a platinum group metal component. The prepared catalyst article may be suitable for the treatment of emissions from an internal combustion engine or a gas turbine, for example, the treatment of carbon monoxide and/or formaldehyde emissions from a natural gas fueled internal combustion engine or gas turbine.

The present invention relates to a method of preparing a catalyst article comprising steps: (a) preparing a washcoat composition by combining at least the following components: a support material comprising a mixed oxide, a mixture of oxides or a molecular sieve comprising (i) alumina and (ii) silica and/or zirconia; a metal oxide sol comprising at least one of titania, silica or zirconia; a liquid medium; (b) applying the washcoat composition to a substrate to form a washcoating; and (c) drying and/or calcining the washcoating; wherein the method further comprises a step of impregnating the support material with a platinum group metal component. The prepared catalyst article may be suitable for the treatment of emissions from an internal combustion engine or a gas turbine, for example, the treatment of carbon monoxide and/or formaldehyde emissions from a natural gas fueled internal combustion engine or gas turbine.

Provided is an SCR catalyst article comprising a substrate having thereon a second catalyst composition downstream of a first catalyst composition, wherein the first and second catalyst compositions are different and wherein the first catalyst composition is an SCR catalyst composition and the second catalyst composition comprises an Fe-loaded small- or medium-pore molecular sieve, the small- or medium-pore molecular sieve having a silica-to-alumina ratio (SAR) of from 6 to 19.