Mingshu Chen

Syngas (CO/H ₂ ), sourced from coal, biomass, and shale gas, plays a crucial role in producing a wide range of industrially essential hydrocarbons and oxygenates through Fischer–Tropsch synthesis and its variations. Despite extensive research dating back nearly a century, transforming syngas into higher alcohols remains challenging due to issues with low selectivity and catalyst instability. Generally, more than 50% of CO in typical syngas conversions yields unwanted hydrocarbons, mainly alkanes. Herein, we develop a catalyst integrating a Mo ₂ C-matrix-supported CuCo alloy with hydrophobic graphitic carbon overlayers, achieving 80% selectivity toward value-added alcohols and olefins, of which 59% are higher alcohols, while limiting alkanes to around 10%. The overlayers dynamically participate in the reaction through carbon consumption and replenishment, generating carbon-overlayer-derived CH _x species that form an asymmetrically polarised coupling pair with CO-derived intermediates, thereby lowering the barrier for CO insertion and diverting CO from deoxygenation pathways leading to alkane and coke formation. Consequently, the yield of value-added products reaches four times that of typical benchmarks at 80% CO conversion with long-term stability. This work represents a substantial advance in higher alcohol synthesis and sheds new light on the catalytic role of surface carbon in syngas conversion.

Most heterogeneous catalysts undergo dynamic changes under reaction conditions. In this study, the redox properties and dynamic behavior of CuOx/γ-Al2O3 catalysts were characterized using in situ FTIR, quasi-in situ XPS, and HS-LEIS (high-sensitivity low-energy ion scattering spectroscopy), along with XRD, H2-TPR, and CO-TPR. The topmost surface coverage of Cu species was estimated from HS-LEIS, and the oxidation states were investigated by XPS and CO-FTIR under various conditions. The results show that oxidation of the CuOx/γ-Al2O3 catalyst leads to the formation of highly dispersed Cu2+ species, which are somewhat difficult to be reduced by H2 and stable under CO oxidation conditions. A transient high activity for CO oxidation was observed for the pre-reduced catalyst. Additionally, oxidation and redispersion from Cu0 nanoparticles to highly dispersed Cu+/Cu2+ species were observed in the pre-reduced catalysts in a CO/O2/He mixture. The highly dispersed Cu+/Cu2+ species exhibited greater activity for CO oxidation and were more easily reduced by H2 than the highly dispersed Cu2+ species. The active copper species and structure–activity relationships were correlated.

Shale gas, a mixture of methane (CH ₄ ), ethane (C ₂ H ₆ ), and propane (C ₃ H ₈ ), provides an alternative feedstock for producing chemicals in industry. As the increasing energy crisis and environmental concern, the conversion of shale gas to value‐added chemical in a sustainable manner has emerged as a new frontier yet remains great challenges. Herein, we realize the solar‐driven conversion of shale gas into alcohols over ZnO nanomeshes incorporated with Ni nanoparticles (Ni/ZnO NM) with oxygen and water. Specifically, the isopropanol yield from C ₃ H ₈ oxidation reaches 7.1 mmol g ⁻¹ h ⁻¹ at a selectivity of 83.5%, with an apparent quantum efficiency (AQE) of 0.65% at 350 nm, surpassing the reported catalysts for propane‐to‐oxygenates. Moreover, both the selectivity of methanol and ethanol surpass 90% from solar‐driven CH ₄ and C ₂ H ₆ oxidation. Impressively, a mixture of methane, ethane, and propane, the analogue of shale gas, can be selectively converted into methanol, ethanol, and isopropanol. Mechanism studies suggest the strong interaction induces electron transfer from ZnO to Ni and creates electron‐rich Ni sites and electron‐deficient oxygen vacancies (Vo) in ZnO NM. Under light irradiation, electron‐rich Ni sites and electron‐deficient Vo can serve as hole and electron acceptors, respectively, promoting the separation of photogenerated carriers and enhancing performance toward alkane oxidation.

The catalytic versatility of the copper surface calls for a fundamental understanding of the formation and reactivity of key intermediates in various C₁ catalytic conversions such as water-gas shift reaction, CO/CO₂ hydrogenation, and electrochemical reduction reactions. Here, based on in situ spectroscopic and morphological evidence, we demonstrate the formation of a bridge CO* species through the adsorption-induced restructuring of a defect-rich Cu surface and its reactivity toward C-O bond dissociation and C-C coupling under hydrogenation reaction conditions. In corroboration with computational simulations, we attribute the unexpected reactivity to its enhanced adsorption strength and polarity with respect to commonly observed on-top CO* species. Our findings provide new insights into the strong correlation between the surface defect density and the selectivity toward methane, C₂ hydrocarbons, and oxygenates over Cu-based catalysts. The marked impact on reactivity highlights the crucial role of dynamic surface restructuring in determining the reaction selectivity over copper-based catalysts.

In the chemical industry, an elaborated design of catalysts for propane dehydrogenation (PDH) should be capable of high propane conversion and propylene selectivity, strong resistance to sintering and coke deposition, and easy regeneration. Here, we report a unique design of fluorinated siliceous MFI zeolite-clothed PtSn for PDH, where the fluorination induces the formation of "holes" in all-silica molecular sieves and the position of ultrasmall PtSn nanoclusters as a result of high activity, selectivity, and especially remarkable resistance to sintering during PDH over 5000 h. The present catalyst displays a near-thermodynamic-limited propane conversion and 94% propylene selectivity in pure propane, respectively, under industrially relevant conditions. Impressively, the coked catalyst can be simply regenerated by H₂ treatment at the same temperature for PDH, avoiding the complicated, poisonous, and corrosive oxychlorination process in the conventional method for regeneration, which will contribute to the extensive application of the industrial PDH process. Detailed investigations demonstrate that the strong synergy between F-modified PtSn nanoclusters and MFI zeolite can promote the selective PDH to propylene and stabilize PtSn nanoclusters against sintering and coke deposition. The unique design of the catalyst and the enhanced performance will provide a feasible strategy to solve the current difficulties in the industrial PDH process.

Methylcyclohexane dehydrogenation (MCHDH) is vital in hydrogen storage and carriage technologies. However, Pt/Al₂O₃, as a classic practical catalyst for MCHDH, remains ambiguous regarding the catalytic structure of active Pt sites for C-H activation at the atomic scale due to a shortage of subnanometer characterization. Here, based on comprehensive structural characterizations and density functional theory (DFT) calculations, we demonstrate optimal active Pt sites: two-dimensional (2D) submonolayer clusters (SLCs) interfaced with γ-Al₂O₃ with an appropriate ratio of Pt^δ+ to Pt⁰ to form optimal Pt⁰-Pt^δ+ interfacial sites that have superior activity for the MCHDH reaction. This SLC's catalyst achieves a reaction rate of up to 29,353 mmol g_Pt^-1 min^-1 at 320 °C, with a 99.98% selectivity for toluene over MCHDH, which is significantly better than that of the corresponding Pt single atoms and conventional Pt nanoparticles (NPs) catalysts. The excellent MCHDH performance of Pt 2D SLCs is attributed to their sufficient 5d-electron domination and the optimal Pt⁰-Pt^δ+ sites, which facilitate the sequential activation of multiple C-H bonds and toluene desorption. In comparison, the presence of too many continuous Pt⁰-Pt⁰ sites in Pt 2D SLCs can hinder these processes. Our study highlights that constructing atomic-scale 2D submonolayer metal clusters is a promising strategy for optimizing efficient catalysts with abundant M⁰-M^δ+ (M = metal) sites, enhancing the catalytic performance for selective C-H bond activation.

SiO₂ supported Rh-based catalysts have been extensively used in CO hydrogenation reactions. The incorporation of promoters into the Rh/SiO₂ catalyst modulates the charge on Rh, subsequently enhancing its activity and selectivity toward C₂ oxygenates. Despite this, the structural and electronic properties of the Rh-SiO_x interface have not been exhaustively explored. In this study, silicon was evaporated onto the Rh(111) surface, followed by annealing in O₂ to form ultrathin SiO_x films. The results indicate that SiO_x films grow on the Rh(111) surface in a layer-plus-island mode. The stabilities of the SiO_x-Rh interface in O₂ with an elevated pressure and vacuum annealing were examined. Both O₂ and CO can adsorb in the interface of SiO_x-Rh in elevated pressures. The binding energies of Si 2p and O 1s shift as oxygen is adsorbed in the interface. The results provide evidence for the activation of small molecules in the metal-oxide interface, and show a passivation effect of an oxide coated metal surface.

ZnCrO_x oxides coupled with zeolites (OXZEO) allow direct conversion of syngas into light olefins, while active sites in the composite oxides remain elusive. Herein, we find that ZnO particles physically mixed with ZnCr₂O₄ spinel particles can be well dispersed onto the spinel surfaces by treatment in syngas and through a reduction-evaporation-anchoring mechanism, forming monodispersed ZnO_x species with uniform thickness or dimension on ZnCr₂O₄ up to a dispersion threshold ZnO loading of 16.0 wt% (ZnCr₂O₄@ZnO_x). A linear correlation between CO conversion and surface ZnO loading clearly confirms that the ZnO_x overlayer on ZnCr₂O₄ acts as the active structure for the syngas conversion, which can efficiently activate both H₂ and CO. The obtained ZnCr₂O₄@ZnO_x catalyst combined with SAPO-34 zeolite achieves excellent catalytic performance with 64% CO conversion and 75% light olefins selectivity among all hydrocarbons. Moreover, the ZnO_x overlayer is effectively anchored on the ZnCr₂O₄ spinel, which inhibits Zn loss during the reaction and demonstrates high stability over 100 hours. Thus, a significant interface confinement effect is present between the spinel surface and the ZnO_x overlayer, which helps to stabilize ZnO_x active structure and enhance the catalytic performance.