Dual-Functional Catalyst of Amorphous TiO2 Embedded in Mesoporous Carbon Hollow Spheres for H2O2 Electrosynthesis

H 2 O 2 production in coupled electrochemical systems, where H 2 O 2 is generated through 2e-pathway of water oxidation (2e-WOR) at anode and 2e-pathway of oxygen reduction (2e-ORR) at cathode, offers an advanced alternative to the anthraquinone process. However, the efficiency of such coupled system is often hindered by the limited activity and selectivity of electrocatalysts. Herein, a dual-functional catalyst composed of amorphous TiO 2 embedded in mesoporous carbon hollow spheres (TiO x @MCHS) is reported, which exhibits exceptional electrocatalytic performance for both 2e-WOR and 2e-ORR. By employing TiO x @MCHS-loaded electrodes as both anode and cathode in a membrane-free flow cell with 4 м K 2 CO 3 /KHCO 3 as electrolyte, a rate of 108.3 µmol min −1 cm −2 and a Faradaic efficiency (FE) of ≈145% for H 2 O 2 production are achieved at a voltage of ≈2.5 V under a constant current of 240 mA (anode: 1 cm 2 , cathode: 4 cm 2 ). Experimental and computational results reveal the crucial role of low-coordinated Ti in optimizing the adsorption of intermediates involved in the two electrode reaction pathways, thereby enhancing both activity and selectivity of these processes. This work establishes a new paradigm for the development of advanced electrocatalysts and the design of novel coupled-electrolysis systems, enabling scalable and sustainable H 2 O 2 electrosynthesis.