Table 2. Summary of HEOs for thermocatalysis, electrocatalysis, and photocatalysis.
T, thermocatalysis; E, electrocatalysis; P, photocatalysis.
| Material | Structure | Synthetic method | Catalytic reaction | Ref. |
| NiMgCuZnCoOx | Rock salt | Template method | Aerobic oxidation of benzyl alcohol (T) | (8) |
| Rock salt | Solid-state synthesis | CO oxidation (T) | (48) | |
| MoNiCuZnCoOx | Rock salt | Solid-state synthesis | Oxidative desulfurization (T) | (115) |
| NiMgCuFeCoOx-Al2O3 | Rock salt + amorphous (binary) | Nonhydrolytic sol-gel strategy + ball milling |
CO oxidation (T) | (116) |
| CuCeOx-NiMgCuZnCoOx | Fluorite + rock salt (binary) | Ball milling | CO oxidation (T) | (117) |
| TiZrHfNbTaO11 | Monoclinic + orthorhombic (binary) |
High-pressure torsion | HER (P) | (119) |
| (CoCuFeMnNi)3O4 | Spinel | Solvothermal synthesis | OER (E) | (120) |
| FeMgCoNiOx | Spinel + rock salt | Sol-gel + solid-state synthesis | Water splitting (T) | (121) |
| Pt1/NiMgCuZnCoOx | Rock salt | Coprecipitation + solid-state synthesis |
CO oxidation (T) | (122) |
| Ru/NiMgCuZnCoOx and Pt/ NiMgCuZnCoOx |
hcp/rock salt and fcc/rock salt | Ball milling | CO2 hydrogenation (T) | (123) |
| Ru/BaSrBi(ZrHfTiFe)O3 | Perovskite | Sonochemical synthesis | CO oxidation (T) | (124) |
| ZrCeMgLaYHfTiCrMnPdOx | Fluorite | Carbothermal shock | Methane combustion (T) | (37) |
| Pd1/CeZrHfTiLaOx | Fluorite | Ball milling + calcination | CO oxidation (T) | (31) |
| Au/NiMgCuZnCoOx | fcc/rock salt | Solid-state synthesis | CO oxidation (T) | (126) |