(2026) Journal of Science: Advanced Materials and Devices_Engineering metallic palladium-copper interfaces on titanium dioxide for efficient catalytic abatement of gaseous benzene

Vikrant K.; Chung M.W.; Weon S.; Boukhvalov D.W.; Baitimbetova B.; Heynderickx P.M.; Kim K.-H.; Kwon E.E.

(Elsevier B.V.) Journal of Science: Advanced Materials and Devices ISSN: 24682284 Vol.11 Issue.4 Article No.101279 DOI: 10.1016/j.jsamd.2026.101279

The cancer-causing aromatic volatile organic compound (VOC), benzene, is a common contaminant found in the air. In this study, a reductively engineered palladium (Pd)-copper (Cu) nanoalloy supported on titanium dioxide (TiO₂) is prepared to study an exothermic pathway for the rate-limiting benzene ring-opening step via thermocatalytic oxidation. The catalysts are synthesized via wet impregnation, with controlled Pd loading followed by either oxidative (O: air calcination) or reductive (R: hydrogen (H₂) treatment at 300°C) pre-treatment. The R pre-treatment generates metallic Pd₀-Cu₀ nanoalloys on TiO₂, while the O counterpart yields isolated metal oxides. The ranking of catalytic activity for 100 ppm benzene, under experimental conditions of 250°C, gas hourly space velocity of 79,618 h⁻¹, and 0% relative humidity, is as follows: Pd/Cu-TiO₂-R (71 ± 7.9 μmol g⁻¹ h⁻¹) > Cu-TiO₂-R (59 ± 0.27) > Pd/Cu-TiO₂-O (42 ± 3.4) > Cu-TiO₂-O (23 ± 0.27). The top-performing Pd/Cu-TiO₂-R catalyst also achieves the highest CO₂ yield (78.2% across 250 to 550°C). Density functional theory simulations demonstrate the mechanistic origin of this enhancement: the reductively engineered Pd-Cu nanoalloy surface provides an exothermic pathway for benzene ring-opening, whereas the oxidized surface imposes an endothermic barrier. Increased moisture (up to 60% RH) competes with benzene for active sites, reducing benzene conversion from 41.4% to 26.7%. By purposefully creating metallic Pd₀-Cu₀ interfacial sites on Pd-Cu/TiO₂ nanoalloys through a rational reductive engineering process, this research unlocks an energetically advantageous ring-opening chemical reaction, thereby forging a new design strategy for the oxidation of aromatic VOCs under mild temperature conditions. © 2026 Vietnam National University, Hanoi.

This work was supported by a grant from the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (MSIT) of the Korean government (Grant Number: 2021R1A3B1068304)and by the CLEAN-AIR (Comprehensive Low Emission & Advanced Monitoring Network for Air Improvement & Renewal) R & D Program under grant number RS-2026- 25504540. This work is financially supported by VinUniversity under Grant Number VINUNI.2526.CMIT.02. P.M.H. would like to thank the Research and Development Program of Ghent University Global Campus (GUGC), Korea.