fig1

Figure 1. (A) Heating principles of conventional fired reactor and electric resistance-heated reactor. Reprinted with permission from Ref.^[18]. Copyright 2019, The American Association for the Advancement of Science; (B) Schematic diagram of isotopic oxygen exchange process under thermal and current-assisted conditions. Reprinted with permission from Ref.^[19]. Copyright 2025, Wiley-VCH.