EXAFS in situ: The effect of bromide on Pd during the catalytic direct synthesis of hydrogen peroxide

摘要: Abstract The direct synthesis of hydrogen peroxide is catalyzed by palladium catalysts supported over different solids. With the aid a suitable plug-flow reaction cell, we carried out preliminary X-ray absorption fine structure spectroscopy (EXAFS) characterization catalyst on commercial resin K2621 under conditions (in situ). Whereas catalyst, which in dry presents metal Pd and PdO when fresh, practically unaffected medium (methanol) or mixture (CO2/H2/O2, 86/10/4, v/v) it undergoes an apparent reduction part to some leaching during presence bromide ions. These findings suggest role ions as enhancers selectivity could not be limited selective blocking sites responsible for undesired formation water, but also entail phase modifications active metal.