Developing efficient and durable noble-metal-free catalysts for low-temperature CO oxidation remains a challenge, as conventional transition metal oxides are plagued by sintering, limited active-site accessibility, and poor oxygen activation capability. Herein, a facile and scalable ultrasonic-assisted strategy was developed to synthesize a Ce-doped high-entropy metal–organic framework precursor (6-HE-MOF), followed by controlled calcination to obtain high-entropy oxide (HEO) catalysts. Among them, 6-HEO-550 exhibited the highest catalytic efficacy, achieving complete CO conversion at 140 °C and preserving 100% conversion across a 50 h continuous stability test at 140 °C. Comprehensive structural and surface characterizations reveal that the MOF-derived architecture effectively suppresses particle sintering while preserving an open mesoporous structure with a high specific surface area (60.3 m2 g−1), thereby facilitating active-site exposure and mass transport. Meanwhile, Ce incorporation enriches oxygen vacancies and reactive adsorbed oxygen species. In situ DRIFTS further demonstrates that Ce promotes CO chemisorption and accelerates the formation and conversion of reactive carbonate intermediates, resulting in a reduced apparent activation energy of 51.8 kJ mol−1. This work demonstrates that coupling high-entropy multicomponent engineering with Ce-induced defect modulation through a MOF-derived strategy provides an effective and scalable route for developing highly efficient, durable, and noble-metal-free catalysts for low-temperature CO oxidation.
Magnesium and its alloys exhibit unique advantages in mechanical properties due to the low density and high specific strength. However, fast corrosion and poor resistance to biofouling largely limit their extensive applications. In this study, a multi-layer protective strategy is proposed, composed of a calcium carbonate porous bottom layer, a hydrophobic surface (HS) via modification and a slippery liquid-infused porous surface (SLIPS). This composite structure can remarkably inhibit the penetration of corrosive media and maintain the stability of surface hydrophobicity owning to the retention of infused oil into porous CaCO3 coating and the physical barrier against corrosive solution. The results revealed that the static water contact angle of SLIPS-coated Mg alloy exceeds 90°, demonstrating excellent hydrophobicity. Meanwhile, stability tests and electrochemical measurements verified significantly improved corrosion resistance for SLIPS samples than the bare substrate, and the SLIPSs can maintain long-term hydrophobic performance in simulated seawater. Bacterial adhesion assays demonstrated that the coverage rates of E. coli and S. aureus on the SLIPSs dropped below 0.25%, revealing a remarkably anti-biofouling ability. These presented results provide an innovative solution and implementation approach for maintaining the long-term corrosion resistance and anti-biofouling stability for Mg alloys.
