Conventional gold-based catalysts, and particularly nanoporous gold-based catalysts either consist of the nanoporous gold material, or are formed by depositing gold on and/or within metal oxides to form an active structure. While these conventional structures exhibit beneficial activity at relatively low temperatures (e.g. about 0 centigrade), as temperature increases the activity degrades due to the nanoporous gold material forming aggregates (e.g. by sintering), reducing the surface area of the overall structure and thus the catalytic activity thereof.
This is particularly undesirable for use in applications to which such catalysts have been earnestly researched. In particular, for an engine (in particular an internal-combustion engine) that operates at a wide range of temperatures, a catalyst that could efficiently treat exhaust gas both in a cold-start phase and at a peak-operation phase when the engine is hot (e.g. several hundred centigrade) would be beneficial.