Surface Cleaning and Protection Engineering via Functionalization to Awaken the Intrinsic Catalytic Activity of Co₃O₄

Abstract

The inherent catalytic activity of transition metal oxide catalysts is constrained by the presence of surface hydroxyl groups, which are typical destructive poisons that are difficult to be completely removed. So, previous studies generally focused on reducing the accumulation of hydroxyl groups on the surface by introducing additional elements. In this study, a simple reflux treatment in methanol considerably increases the CO oxidation activity, water resistance, and stability of Co3O4. According to the density functional theory calculations, the cleaning of hydroxyl groups by methanol is spontaneous, and the assembled methanol has little effect on the surface chemical properties. In addition, the molecular dynamics simulations indicate that methanol molecules have formed hydrophobic entrances in the pores of Co3O4, which further protect the internal surface from erosion by water. Furthermore, methanol functionalization maintains the original CO oxidation mechanism on the clean Co3O4 surface. As a result, the inherent catalytic activity of Co3O4 is awakened while the water resistance and stability are improved. Collectively, this study establishes an atomic‐level description for the surface cleaning and protection mechanism on Co3O4 surface through functionalization by small organic molecules, which provides a new theoretical guidance for the modification strategies of transition metal oxide catalysts.

Unveiling the Critical Role of Surface Hydroxyl Groups for Electro-Assisted Uranium Extraction from Wastewater

“…Figure e shows the FT-IR spectroscopy of A-CoO x and CoO x . CoO x displayed two distinct characterized peaks at 1400–1260 and 3000–3700 cm –1 , which were attributed to the bending vibration of hydroxyl groups. , After annealing, the hydroxyl characteristic peak area of A-CoO x was significantly reduced, further confirming that the surface of CoO x was rich in hydroxyl groups. Figure S6 displays the TGA curve of A-CoO x and CoO x .…”

Precise Design of TiO2@CoOx Heterostructure via Atomic Layer Deposition for Synergistic Sono‐Chemodynamic Oncotherapy

“…The decrease in the impedance arc radius of TiO 2 @100CoO x relative to TiO 2 suggests that the deposition of CoO x decreases electronic impedance and increases carrier density and electron diffusion (Figure 3f), thereby favoring subsequent electron and hole reactions and SDT performance. [ 22 ]…”

Modulating the Electronic Structures of Pt on Pt/TiO2 Catalyst for Boosting Toluene Oxidation

“…Volatile organic compounds (VOCs), especially benzene, toluene, and xylene, are considered to be harmful to human health (teratogenic and carcinogenic effects) and linked with environmental hazards (ozone and photochemical smog). − The catalytic oxidation of VOCs has been recognized as a green and efficient technology for VOC treatment, where the design and preparation of catalysts are the core. − In the process of catalyst preparation, hydroxyl groups inevitably existed on the catalysts due to the dissociation of water molecules. , Surface hydroxyl groups on the catalyst can play a role in the promoting or inhibiting effect in the catalytic oxidation of pollutants. To be specific, surface hydroxyl groups as the active oxygen species could markedly enhance the catalytic activity of HCHO oxidation by the fast reaction step ([HCOO – ] + [OH] → CO 2 + H 2 O) .…”