Bimetallic Cu-Pt catalysts over nanoshaped ceria for hydrogen production via methanol decomposition

CO-Tolerant Pt1-MoOx/Mo2N Catalyst for Efficient Activation of C-H and O-H Bonds toward Alcohol Dehydrogenation

Excessively strong adsorption of CO onto a Pt-based catalyst results in the poisoning effect during numerous CO-containing catalysis reactions, including the dehydrogenation process of alcohols. Traditional strategies via modifying the electronic state of Pt atoms are beneficial for weakening CO adsorption; however, they are normally detrimental to C-H cracking, thereby degrading catalytic efficiency toward alcohol dehydrogenation reaction. In this work, we present a synergistic function of Pt1 single atoms and heterostructured MoOx/Mo2N for efficiently dehydrogenating alcohols, allowing high CO resistance along with excellent capacity for C-H and O-H activation. This conjunction renders electron transfer via a strong Pt-MoOx/Mo2N interaction and thus induces the low 5d occupancy of Pt sites, enabling the facile CO desorption, which thereby boosts the efficiency of entire reaction cycles. Based on in situ structural characterizations and isotopic labeling analysis, we found that the spontaneously formed thin MoOx-Ov layer enables the barrierless breakage of O-H bonds even at as low as room temperature, which further energetically facilitates C-H cracking on interfacial Pt1 sites. Therefore, this strategy can be applied to fabricate CO-tolerant Pt-based catalysts toward numerous CO-containing reactions without compromising reactivity by coupling the advantages of single-atom and defective support materials.

Solar-Driven Hydrogen Production from Methanol Decomposition Catalyzed by High-Entropy Spinel Oxides

To address safety and economic issues in hydrogen storage and transportation, developing liquid organic hydrogen carriers to deliver hydrogen to where it can be utilized for in situ hydrogen production is an attractive approach. Herein, a spinel phase high-entropy oxide (HEO) (FeCrCoNiCu)3O4 comprising of non-noble metals is synthesized via the PVP (Polyvinyl Pyrrolidone)-templated method as a catalyst for solar-driven hydrogen production through methanol decomposition. Benefiting from the synergistic effects of various components in high-entropy materials, (FeCrCoNiCu)3O4 HEO achieves an optimized hydrogen production rate of 49.4 mmol g-1 min-1, with a surface temperature of 279 °C under full-spectrum illumination of 2.68 W cm-2. The performance is significantly higher than that under thermocatalytic conditions at the same temperature and surpasses the activity of the state-of-the-art catalysts. The catalyst exhibits long-term stability over 80 h through in situ removing deposited carbon, and thus HEOs show great promise for efficient hydrogen production from methanol decomposition under mild conditions.

Recent progress of heterogeneous catalysts for transfer hydrogenation under the background of carbon neutrality

Under the background of carbon neutrality, the direct conversion of greenhouse CO2 to high value added fuels and chemicals is becoming an important and promising technology. Among them, the generation of liquid C1 products (formic acid and methanol) has made great progress; nevertheless, it encounters the problem of how to use it efficiently to solve the overcapacity issue. In this review, we suggest that the catalytic transfer hydrogenation using formic acid and methanol as the hydrogen sources is a critical and potential route for the substitution for the fossil fuel-derived H2 to generate essential bulk and fine chemicals. We mainly focus on summarizing the recent progress of heterogeneous catalysts in such reactions, including thermal- and photo-catalytic processes. Finally, we also propose some challenges and opportunities for this development.

Synthesis and Characterization of Stable Cu-Pt Nanoparticles under Reductive and Oxidative Conditions

We report a synthesis method for highly monodisperse Cu-Pt alloy nanoparticles. Small and large Cu-Pt particles with a Cu/Pt ratio of 1:1 can be obtained through colloidal synthesis at 300 °C. The fresh particles have a Pt-rich surface and a Cu-rich core and can be converted into an intermetallic phase after annealing at 800 °C under H₂. First, we demonstrated the stability of fresh particles under redox conditions at 400 °C, as the Pt-rich surface prevents substantial oxidation of Cu. Then, a combination of in situ scanning transmission electron microscopy, in situ X-ray absorption spectroscopy, and CO oxidation measurements of the intermetallic CuPt phase before and after redox treatments at 800 °C showed promising activity and stability for CO oxidation. Full oxidation of Cu was prevented after exposure to O₂ at 800 °C. The activity and structure of the particles were only slightly changed after exposure to O₂ at 800 °C and were recovered after re-reduction at 800 °C. Additionally, the intermetallic CuPt phase showed enhanced catalytic properties compared to the fresh particles with a Pt-rich surface or pure Pt particles of the same size. Thus, the incorporation of Pt with Cu does not lead to a rapid deactivation and degradation of the material, as seen with other bimetallic systems. This work provides a synthesis route to control the design of Cu-Pt nanostructures and underlines the promising properties of these alloys (intermetallic and non-intermetallic) for heterogeneous catalysis.