Mesoporous gold sponges

Figure 7.5 Two topologically distinct types of mesoporous gold sponge, each with 50 volume % gold, (a) Swiss-cheese morphology produced by de-alloying, (b) aggregated particle morphology produced by sintering of nanoparticles.

In any case, it is interesting to note that catalytic efficacy has been observed with nano- or mesoporous gold sponges [99-101, 145] suggesting that neither a discrete particle nor an oxide support is actually a fundamental requirement for catalysis. An alternative mechanism invokes the nanoscale structural effect noted in Section 7.2.2, and proposes that the catalytic effect of nanoscale gold structures is simply due to the presence of a large proportion of lowly-coordinated surface atoms, which would have their own, local electronic configurations suitable for the reaction to be catalyzed [34, 49,146] A recent and readily available study by Hvolbaek et al. [4] summarizes the support for this alternate view. 

Mesoporous gold sponge as a prototype meta-materiar, A. Maaroof, M. B. Cortie, and G. B. Smith, Phys. B, 2007, 394, 167. 

There has been some interest in mesoporous sponges of gold [96, 97]. These structures combine the electrical conductivity of gold with a very high surface area. 

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