Xiaodong Yi

Solar-driven conversion of CO2 into value-added chemicals provides an effective pathway for carbon resource utilization. However, the sluggish kinetics of CO2 reduction and the reliance on sacrificial electron donors limit its practical viability. Herein, we present a bifunctional photocatalyst consisting of spatially separated Ag2S and Au cocatalysts anchored on hollow CdS (Ag2S-Au/CdSH), which enables efficient concurrent CO2 photoreduction to CO and selective oxidation of aryl alcohols to benzaldehyde in a sacrificial-agent-free system. The rational integration of dual-active sites induces oriented charge flow, significantly enhancing photogenerated carrier separation and utilization, as evidenced by ultrafast spectroscopy showing extended electron lifetimes. This synergistic architecture delivers markedly higher production rates of 1.2 mmol g–1 h–1 for CO and 2.5 mmol g–1 h–1 for benzaldehyde, representing approximately 8-fold and 5-fold enhancements over pristine CdS, respectively. Comprehensive in situ spectroscopic studies combined with density functional theory calculations elucidate the distinct roles: Au sites strengthen CO2 adsorption and stabilize intermediates for reduction, while Ag2S promotes alcohol dehydrogenation. This synergistic dual-site architecture maximizes redox efficiency by matching reaction potentials and minimizing carrier recombination. This work provides mechanistic insights into catalyst design for integrated CO2 valorization and biomass upgrading, providing a basis for efficient chemical production.

Efficient acidic CO2 electroreduction to formic acid (HCOOH) offers a promising pathway for chemical manufacturing, yet catalyst stability remains a major obstacle. For example, while In2O3 catalysts exhibit high selectivity toward HCOOH, the cationic In3+ species are prone to reduction to metallic In under harsh acidic conditions. Herein, we demonstrate that high-valent In3+ species are dynamically regenerated by integrating In/In2O3 heterointerfaces with periodic anodic pulses, preventing the irreversible deactivation observed under conventional steady-state conditions. Combined in situ characterizations and theoretical calculations reveal that the heterointerface enhances *OCHO intermediate formation and accelerates interfacial water dissociation to supply abundant *H, enabling highly efficient and stable HCOOH production. As a result, the In/In2O3 catalyst achieves a HCOOH Faradaic efficiency of 95.5% at –1.0 A cm–2 and maintains stability for 133 h under pulsed electrolysis in pH 2 electrolyte, significantly outperforming the neat In catalyst. Moreover, concentrated HCOOH (1.43 M) is directly produced at –0.4 A cm–2 in a solid-state electrolyte reactor. This work demonstrates that metastable high-valent active sites can be sustained under industrially relevant acidic CO2 electrolysis through synergistic interfacial stabilization and dynamic electrochemical regeneration, providing a universal strategy for catalyst-state management in electrochemical systems.

Electrochemical CO₂ reduction reaction in acidic media is fundamentally limited by competitive hydrogen evolution and poor selectivity toward multi-carbon products. Here we report a cooperative catalytic strategy that enables highly selective multi-carbon formation under strongly acidic conditions by regulating proton activation and interfacial solvation. By exploiting the copper oxide nanosheets and integrating an immobilized cobalt tetra(4-carboxyphenyl)porphyrin, a dual-functional interface is constructed that steers abundant protons toward productive C-C bond formation. This synergy sustains C-C coupling at high current densities and suppresses parasitic hydrogen evolution. As a result, the hybrid catalyst delivers a multi-carbon Faradaic efficiency of up to 89.5% with partial current densities exceeding 1 A cm^-2 in pH 2 ± 0.1 electrolyte, and maintains high selectivity even at pH 0.7 ± 0.05. Operando spectroscopic analyses and theoretical calculations reveal that regulated proton activation enables efficient formation of key C-C coupling intermediates and stabilizes the catalytic interface under acidic conditions. These results demonstrate a viable route to achieve efficient CO₂ electroreduction to multi-carbon products in acidic environments through molecular control of proton utilization.

Electrocatalytic CO₂ reduction reaction (CO₂RR) technology holds significant industrial potential. However, when faced with elevated-temperature environments caused by industrial-scale operations, the fundamental understanding of temperature-dependent CO₂RR behavior in flow cells remains elusive. This study points out that elevated-temperature operation (>333 K) presents both challenges and opportunities for multi-carbon (C₂₊) production. While elevated temperature enhances reaction kinetics and reduces thermodynamic energy barriers, it simultaneously induces reconstruction of Cu-based catalyst, accelerates gas diffusion electrode flooding, and promotes *CO desorption together with hydrogen evolution reaction, collectively suppressing C₂₊ product formation and compromising long-term reactor stability. Through rational design of hydrophobic-enhanced Pd-Cu₂O/polytetrafluoroethylene (PTFE)/Ag tandem electrodes, we overcome these challenges. Leveraging thermal reduced C-C coupling barriers, the optimized electrode achieves >70% Faradaic efficiency of C₂₊ across industrially relevant current densities (200–1000 mA cm⁻²) at 348 K. This strategy converts elevated temperature adversity into a kinetic and thermodynamic advantage, boosting C₂₊ cathodic energy efficiency by 1.3 times compared to ambient operation, establishing a promising paradigm for industrially viable CO₂ electrolysis.

Hydrodeoxygenation (HDO) of phenolics is crucial for lignin-to-fuel production via fast pyrolysis. The reaction under atmospheric H₂ pressure offers compatibility with pyrolysis conditions, high aromatic selectivity and low H₂ consumption, but suffers from coking-induced catalyst deactivation. In this work, we report a TiO_x-decorated NiSn/SiO₂ catalyst (Ti-NiSn/SiO₂), achieving 100% deoxygenation selectivity and enhanced stability in m-cresol HDO. The superior performance stems from: (i) the interfacial synergy between TiO_x and NiSn alloy that facilitates C-O bond cleavage with a reduced energy barrier; (ii) the geometric isolation and electron-donating properties of Sn, which suppress undesirable side reactions and mitigate coke formation; and (iii) the inverse TiO_x decoration strategy, which enables effective interface chemistry while minimizing acidic sites that could otherwise accelerate coking. This study presents a design strategy for constructing inverse oxide–alloy interface catalysts, offering multi-faceted advantages for HDO and other complex catalytic transformations.

Amorphous aluminosilicates represent a class of important solid acid catalysts. Herein, a series of amorphous aluminosilicate catalysts with tunable Si/Al molar ratios were synthesized for efficient catalytic cracking of cumene.

The pore structure of a hydrotreating catalyst plays a pivotal role in hydrodemetallization (HDM) reactions. To effectively construct a meso-macroporous catalyst, we employed a CTAB-guided in situ TEOS hydrolysis approach to prepare silica-coated γ-Al₂O₃@SiO₂ composite supports. The silica shell incorporation significantly enhances specific surface area and reduces the metal–support interactions, thereby improving the dispersion of NiMo active components and boosting the deposition of metal impurity. Hence, the NiMo/Al₂O₃@SiO₂ catalyst (2.8 wt.% NiO, 4.3 wt.% MoO₃) exhibits much higher HDM activity than that of NiMo/Al₂O₃. This is evidenced by markedly higher demetallization rate constant (1.38 h⁻¹) and turnover frequency (0.56 h⁻¹) of the NiMo/Al₂O₃@SiO₂. The NiMo/Al₂O₃@SiO₂ catalyst further demonstrates excellent recyclability during sequential HDM reactions. This superior catalytic behavior stems from the hierarchical meso-macroporous structure, which simultaneously facilitates the deposition of metal impurities and mitigates deactivation by pore blockage.

Photocatalytic C-N coupling of lactic acid (LA) and ammonia for alanine synthesis provides an attractive route for the upcycling of poly(lactic acid) (PLA) plastic waste. Although several advancements have been made in enhancing the photocatalytic alanine synthesis, current research lacks a clear understanding of how the photocatalyst structure influences the C-N coupling reaction. It is highly desirable to design a rational photocatalyst system to boost the C-N coupling, both for advancing mechanistic understanding and for optimizing catalysis. In this work, we have successfully developed sulfur-vacancy CdS (S_v-CdS) as a photocatalyst, achieving a record-breaking alanine formation rate of 72.5 mmol g_cat^-1 h^-1, which surpasses the highest value reported in the literature to date. More importantly, for the first time, we have demonstrated that the photocatalytic amination of LA to alanine occurs exclusively through a radical pathway, where S vacancies weaken the adsorption of C_α• and NH₂• radicals on the S_v-CdS surface, thereby promoting the C-N coupling. In contrast, Cd vacancies in cadmium-vacancy CdS are more favorable for activation of the C_α-H bond in LA, but they are less effective for the C-N coupling. This work offers further insights into the mechanism of the photocatalytic C-N coupling reaction and opens a practical route for upcycling PLA plastic waste into value-added chemicals.