(98e) Programmable Metals: Metal-Graphene Catalytic Condenser

Manipulation of electron density at catalytically active sites enables regulation of surface chemistry for enhanced rates and selectivity to products. Here, an ultrathin catalytic film of Pt (1 nm) was integrated onto a catalytic condenser device that enabled precise addition or removal of electron from the active metal layer. The catalytic condenser has the following structure: 1 nm Pt/graphene/HfO₂ dielectric (70 nm)/p-type Si substrate. In this study, application of voltages up to ±6V between the graphene and the Si substrate resulted in significant changes in binding energy with either positive or negative charges accumulated on the catalyst. Temperature programmed desorption of CO adsorbed onto Pt revealed a significant shift in peak temperature up to ΔT_peak~±40 ⁰C relative to the uncharged film. Further characterization such as voltage-applied IR spectroscopy, c-TEM, STM, XPS, and UPS were used to verify and to characterize the behavior of the Pt film on the graphene. Overall, the continuous and precise electronic control of metals, such as Pt can be achieved with the catalytic condenser device.