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The interactions of CO2 with indium metal electrodes have been characterized for electrochemical formate production. The electrode oxidation state, morphology, and voltammetric behaviors were systematically probed. It was found that an anodized indium electrode stabilized formate production over time compared to etched indium electrodes and indium electrodes bearing a native oxide in applied potential range of -1.4 to -1.8 V vs SCE. In addition, it was observed that formate is the major product at unprecedentedly low overpotentials at the anodized surface. A surface hydroxide species was observed suggesting a mechanism of formate production that involves insertion of CO2 at the indium interface to form an electroactive surface bicarbonate species.

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Helium atom reflectivity has been used to study the adsorption of a series of n-alkanes, 1-alkenes, and cyclic hydrocarbons on a Au(111) surface. Using this technique, both adsorption and desorption could be observed with high sensitivity under UHV conditions to determine adsorption energies and initial sticking coefficients. For the long-chain n-alkanes studied (C6H14−C12H26), the physisorption energy increases linearly with the chain length by 6.2 ± 0.2 kJ/mol per additional methylene unit. The physisorption energies of the 1-alkenes (C6H12−C11H22) show a similar linear dependence on chain length but are slightly higher than those of the corresponding alkanes. A bond-additive model is presented which is capable of predicting the adsorption energy of 25 saturated and unsaturated hydrocarbons on the basis of four fitted parameters with an average error of 1.9%. Of the molecules considered, 84% of the calculated adsorption energies differ from the experimental value by less than twice the average error. When 10 sulfur-containing compounds and two fitting parameters are added, the average error grows to 2.6%. For all linear hydrocarbons studied, the physisorption sticking coefficient is a function of the reduced surface temperature T*, which is defined as the temperature measured in units of the peak desorption temperature as observed by temperature programmed desorption. The sticking coefficient of each species is close to unity at low temperatures, starts to decrease at T* = 0.8, and reaches zero as the crystal temperature approaches the peak desorption temperature.

A new method is described for surface modification of ITO with an electroactive organic monolayer. This procedure was done to enhance hole injection in an electronic device and involves sequential formation of a monolayer of a pi-conjugated organic semiconductor on the indium tin oxide (ITO) surface followed by doping with a strong electron acceptor. The semiconductor monolayer is covalently bound to the ITO, which ensures strong adhesion and interface stability; reduction of the hole injection barrier in these devices is accomplished by formation of a charge-transfer complex by doping within the monolayer. This gives rise to very high current densities in simple single layer devices and double layer light emitting devices compared to those with untreated ITO anodes.