Mechanism insight into triggering reactive oxygen species generation and HCHO oxidation derived from efficient electron transfer on polar bonds

The behavior of formaldehyde (HCHO) degradation depends strongly on reactive oxygen species (ROS), including singlet oxygen ( 1 O 2 ), superoxide radical (•O 2 - ), and hydroxyl radical (•OH). However, the π electrons in-plane of conventional sp 2 carbon materials are difficult to transfer to the out of plane active site because it is too inert, resulting in an inefficient yield of ROS. This research provides fundamental insights into significantly promoting the ROS generation. Experimental and density functional theory (DFT) computational study reveal that an efficient electron transfer enrichment is achieved from C-N polar bond to N-Pd polar bond to Pd site, which further interact with oxygen molecule to generate •O 2 - (e - + O 2 → •O 2 - ), 1 O 2 (2•O 2 - + 2H 2 O → 1 O 2 + H 2 O 2 + 2OH - ) and •OH (H 2 O 2 + e - → •OH + OH - ), triggering the conversion of HCHO into CO 2 and H 2 O. The results establish that the polar bonds in support are crucial, which provides a new opportunity in designing high performance catalysts.