Determining　the　migration　rules　of　oxygen　species　in　catalytic　combustion,　especially　for　catalysts　composed　of　transition　metal　oxides,　is　essential　yet　challenging.　This　study　hydrothermally　synthesized　nanosphere-structured　cerium　dioxide　(CeO2)　and　its　copper-loaded　catalysts　(Cu/CeO2)　to　identify　the　distinct　functions　of　superficial　oxygen　species　(O)　and　lattice　oxygen　(O2–).　The　presence　of　Cu-Ce　solid　solution　at　the　Cu/CeO2　interface　lowered　the　apparent　activation　energy　for　the　catalytic　combustion　of　propane　and　soot.　The　catalytic　combustion　of　propane　followed　the　Mars-van　Krevelen　mechanism,　with　O2–　serving　as　the　dominant　reactive　phase　while　O　played　a　subordinate　role.　The　solid–solid　reaction　between　soot　and　superficial　oxygen　of　the　catalyst　was　responsible　for　catalyzed　soot　combustion.　The　O　species　produced　by　surface　defective　sites　exhibited　higher　activity　than　O2–,　which　drained　easily　at　the　beginning　of　the　reactions.　The　isotopic　oxygen　exchange　tests　revealed　the　mechanism　of　metal　oxide　(CuO/CeO2)　interactions　for　active　oxygen　species　migration,　with　the　results　demonstrating　the　solid　solution　at　the　phase　interface　as　portholes　for　oxygen　migration,　thus　increasing　oxygen　mobility　between　the　gaseous　phase　and　the　surface　by　lowering　the　migration　activation　energy.　In　situ,　infrared　results　showed　that　the　reaction　path　of　soot　catalytic　combustion　was　single,　without　any　intermediate　production　formation,　compared　to　multiple　paths　in　the　propane　oxidation　process.　This　study　provided　an　easily　implemented　and　widely　applicable　method,　which　deepens　our　understanding　of　the　characterization　of　the　function　and　migration　of　predominant　oxygen　species　in　diverse　combustion　reactions　involving　oxide-based　catalysts.　Additionally,　this　study　clarified　differences　and　similarities　between　the　reaction　mechanisms　of　solid–solid　and　solid–gas　catalysis.　©　2024　Elsevier　B.V.