Nanoporous gold is exceptional among unsupported gold-based catalysts for its ability to activate dioxygen while facilitating partial oxidation reactions analogous to those observed on pristine gold surfaces. This activity is widely attributed to the presence of residual silver in the nanoporous gold as a result of the fabrication methodology. Unfortunately, the complex material properties and morphology of nanoporous gold does not lend itself well to many traditional surface science spectroscopies. Model surface alloys of controlled composition may provide insight into the underlying chemical processes occurring on nanoporous gold. Joshua is currently studying the interactions of dioxygen with Au_xAg_1-x(110) and Ag_xAu_1-x(110) surface alloys. Additionally, he is investigating the effects of the various alloy compositions on processes contributing to carbonate production and the role of the sequestration of oxygen via carbonate formation on reactivity. His research interests include the effect of chemisorption ensemble configurations on reactivity, elucidating fundamental reaction pathways via surface sensitive spectroscopies, and the microkinetic modelling of these mechanisms.

More broadly, he is motivated by a concern over the impact of widely employed chemical processes on local and global climates and how to mitigate these issues via the intelligent design of catalysts for existing chemical transformations and the exploitation of renewable source materials for future chemical needs. Advances in the understanding of nanoscale interactions on the conversion, turn-over, and selectivity of catalytic processes will provide a major framework by which society corrects the unintended tragedy of environmental pollution and climate change as a result of the establishment of parity in global per capita energy consumption.