Adapting an Electron Microscopy Microheater for Correlated and Time-Resolved Ambient Pressure X-ray Photoelectron Spectroscopy

Environmental transmission electron microscopy (ETEM)can followstructural and chemical changes in nanomaterials under reaction conditions,including at temperatures up to 1300 & DEG;C and pressures up to & SIM;20mbar. However, ETEM studies are limited to localized areas of a sampleand can benefit from correlative studies of a similar sample on largerlength scales. Here, we describe the customization of a commercialmicroheater holder used in ETEM to anode-based ambient pressure X-rayphotoelectron spectroscopy (APXPS), where chemical and electronicstructure information is averaged over several hundred square micrometers.To benchmark heating capabilities in the APXPS instrument, core levelbinding energies were followed during surface chemical reactions ofa Pd film, including CO adsorption-desorption, Pd oxidation,and PdO reduction. The fast heating feature of the microheaters advancedXPS experimental capabilities, including the collection of subsecondtime-resolved spectra of the Pd 3d(5/2) peak during the reductionof an oxidized Pd film. The potential to use these heaters in a closedgas cell was also demonstrated by oxidizing Pd in a partial pressureof air locally dosed to the sample surface. General tips and considerationsfor the application of commercial ETEM heaters to any XPS system witha focused X-ray beam are discussed.