A conspicuous discrepancy is prevalent in the characterization of carbon supported palladium catalysts: particle size estimated by XRD and electron microscopy agree, while the chemisorption of hydrogen is substantially suppressed with respect to the small size measured by XRD/STEM. In this work, a systematic study of carbon materials, pretreatments, and characterization has isolated the contributions of carbon decoration and residual chloride, both of which can cause a chemisorption shortfall. The degree of decoration decreases with graphitization of the carbon supports due to stronger C-C interaction, whereas increased density of oxygen functional groups on the surface increases decoration, due to enhanced Pd-C interactions. The discrepancy can be rectified by employing a low temperature burnoff of the decorating carbon layers prior to chemisorption, and by using metal precursors without chloride ligands or counterions.

在碳载钯催化剂的表征中普遍存在明显的差异：通过XRD和电子显微镜估算的粒径一致，而相对于通过XRD / STEM测量的小粒径，氢的化学吸附得到显着抑制。在这项工作中，对碳材料，预处理和表征的系统研究已分离出碳装饰和残留氯化物的作用，这两者都可能导致化学吸附不足。由于较强的CC相互作用，装饰程度随碳载体的石墨化而降低，而由于增强的Pd-C相互作用，表面氧官能团密度的增加也增加了装饰。