Dr Yiyang Li

Abstract:

Herein, a straightforward method is proposed for the selective conversion of CO2 and H2 into propane. This is achieved in a 50 mL batch reactor (45 bar and 230–270 °C) by combining a RhIn/MgOx catalyst with highly acidic ZSM-5 and co-feeding benzene. The addition of 50 mg of benzene is found to be optimal to skew the hydrocarbon selectivity away from C2 and C4–6 towards C3, while maintaining high conversion (>60%) and low CO selectivity (27%) during the 10-hour reaction. Benzene promotes the formation of propane by enhancing the aromatic hydrocarbon pool cycle at the expense of the olefinic cycle. Benzene achieves this by “grabbing” in-situ produced methanol and preventing the over-methylation of aliphatics. In turn, the generated polymethyl benzene species undergo a paring mechanism to produce propylene, which is converted to propane. The role of benzene is elucidated through comprehensive characterisations and extensive control experiments.

Abstract:

Heterogeneous photocatalysis offers a promising route for solar-to-chemical energy conversion, yet its efficiency continues to be constrained by rapid electron-hole recombination and sluggish surface redox kinetics. Recent advances show that integrating external stimuli, such as electric, magnetic, thermal, microwave fields, can provide dynamically tuneable driving forces that influence charge, spin, and lattice behaviour in semiconductors. These external-stimuli interactions enable new mechanisms for promoting charge carrier separation, stabilising intermediates, and modulating interfacial energetics beyond the limits of conventional band-structure engineering. This review presents a comprehensive discussion of external-stimuli-assisted heterogeneous photocatalysis. We examine how different fields interact with semiconductors through various pathways. Representative material platforms, including metal oxides, polar-faceted supports, two-dimensional chalcogenides, are analysed to reveal structure-activity relationships. We further discuss emerging synergistic effects in multi-stimuli systems, where coupled fields create non-linear enhancements in photocatalytic performance. Advances in operando characterisation techniques are highlighted as essential tools for probing these dynamic processes. Together, these developments illustrate how external stimuli can be harnessed to design adaptive, field-responsive photocatalytic systems capable of significantly higher activity, selectivity, and stability. By outlining mechanistic principles, material design strategies, and key challenges, this review provides a framework for developing next-generation solar-to-chemical energy technologies.

Abstract:

Professor Shik Chi Edman Tsang (1962–2025) made sustained and influential contributions to heterogeneous catalysis through a distinctive approach that integrates nanostructure design, advanced characterization, and mechanistic understanding. This Account, written by his former students, highlights the key research themes that defined his scientific career, centered on the principle that catalytic function arises from the controlled interplay of structure, electronic properties, and interfaces at the atomic scale. Early studies on carbon nanostructures and supported nanoparticles established the importance of direct structural observation in understanding catalytic behavior. These foundations evolved into systematic strategies for nanostructure-controlled catalysis. A central theme of Tsang’s work is the role of interfaces and local environment in governing reaction pathways. These principles are exemplified in catalytic processes relevant to energy and sustainability, including hydrogen evolution, CO2 hydrogenation, ammonia synthesis and decomposition, and biomass and plastic conversion. Tsang’s contributions also extend to electrocatalysis and photocatalysis, where atomic-scale design is combined with external driving forces, such as electrical bias, light, and thermal energy. In parallel, the integration of advanced characterization techniques, particularly synchrotron-based methods and electron microscopy, has enabled direct observation of active sites and their evolution under working conditions. Importantly, his work bridges fundamental science and practical application, demonstrating how atomic-level catalyst design can inform scalable technologies for sustainable energy and chemical production.

Abstract:

Developing earth‐abundant electrocatalysts that rival the commercial platinum/carbon catalyst for the hydrogen evolution reaction (HER) remains a central challenge in renewable‐energy conversion. Here, we reveal an electrochemically induced, in situ phase transformation in a Ru‐MgO catalyst that leads to true active material during operation. Under acidic HER conditions, nominal 20 wt.% Ru nanoparticles supported on polar MgO(111) nanocrystals undergo a topotactic hydrolysis to Ru‐Mg(OH)2(001), generating an ordered hydroxide layer that serves as a highly conductive proton‐hopping network. After activation, the catalyst delivers performance comparable to commercial Pt/C under identical conditions, matching the current density of −1.1 V and surpassing it by approximately 10% at −2.3 V. Operando synchrotron X‐ray diffraction combined with ex situ characterization techniques directly captures this transformation, while density‐functional theory calculations reveal that water‐assisted Grotthuss proton transfer across the hydroxide requires only a 0.10 eV energy barrier. These findings establish electrochemically driven oxide‐to‐hydroxide conversion as a new design principle for creating low‐Pt or Pt‐free HER electrocatalysts with intrinsically fast proton transport.