Investigation of Sn Promoter on Ni/CeO Catalysts for Enhanced Acetylene Semihydrogenation to Ethylene.

Ethylene, as an important chemical raw material, could be produced through the coal-based acetylene hydrogenation route. Nickel-based catalysts demonstrate significant activity in the semihydrogenation reaction of acetylene, but they encounter challenges related to catalyst deactivation and overhydrogenation. Herein, the effect of Sn promoter on Ni/CeO catalysts has been comprehensively explored for acetylene semihydrogenation.

Construction of robust Ni-based catalysts for low-temperature Sabatier reaction.

CO hydrogenation to methane, namely, CO methanation or Sabatier reaction, is a significant approach to convert CO and H to storable and transportable CH. Low reaction temperature is the key to industrialization and has attracted plenty of research interest. Ni-based catalysts are commonly utilized owing to their favorable properties of excellent activity and economical price.

Preparation of Sustainable Ni/SiO Catalysts from Rice Husk by Different Methods for CO Methanation.

Silicon dioxide (SiO) from rice husk can be extracted and be used as support for Ni-based catalysts. The impregnation method (IM) is usually used for preparing Ni/SiO catalysts, but its catalytic activity in CO hydrogenation to CH remains unsatisfactory. In this work, we explored alternative preparation methods, using ammonia evaporation method (AEM) and hydrothermal method (HM) to prepare the catalysts.

Visualizing Phase Evolution of CoC for Efficient Fischer-Tropsch to Olefins.

Cobalt carbide (CoC) possesses high catalytic efficiency Fischer-Tropsch synthesis (FTS), while the products selectivity appears sensitive to crystallography geometry. Since the Anderson-Schulz-Flory (ASF) distribution in FTS is broken through fabricating facetted CoC nanocrystals, yet the underlying mechanism of CoC crystallization remains unclarified suffering from sophisticated catalyst composition involving promoter agents. Herein, the synthesis of high-purity single-crystal nanoprisms (CoC-p) for highly efficient FTS is reported to lower olefins.

A Ce-CuZn catalyst with abundant Cu/Zn-O-Ce active sites for CO hydrogenation to methanol.

CO hydrogenation to chemicals and fuels is a significant approach for achieving carbon neutrality. It is essential to rationally design the chemical structure and catalytic active sites towards the development of efficient catalysts. Here we show a Ce-CuZn catalyst with enriched Cu/Zn-O-Ce active sites fabricated through the atomic-level substitution of Cu and Zn into Ce-MOF precursor.

Catalytic CO Oxidation on the Cu-O-Ce Interface Constructed by an Electrospinning Method for Enhanced CO Adsorption at Low Temperature.

It is crucial to eliminate CO emissions using non-noble catalysts. Cu-based catalysts have been widely applied in CO oxidation, but their activity and stability at low temperatures are still challenging. This study reports the preparation and application of an efficient copper-doped ceria electrospun fiber catalyst prepared by a facile electrospinning method.

Biomass gasification, catalytic technologies and energy integration for production of circular methanol: New horizons for industry decarbonisation.

The Intergovernmental Panel on Climate Change (IPCC) recognises the pivotal role of renewable energies in the future energy system and the achievement of the zero-emission target. The implementation of renewables should provide major opportunities and enable a more secure and decentralised energy supply system. Renewable fuels provide long-term solutions for the transport sector, particularly for applications where fuels with high energy density are required.

Boosting Low-Temperature CO Hydrogenation over Ni-based Catalysts by Tuning Strong Metal-Support Interactions.

Rational design of low-cost and efficient transition-metal catalysts for low-temperature CO activation is significant and poses great challenges. Herein, a strategy via regulating the local electron density of active sites is developed to boost CO methanation that normally requires >350 °C for commercial Ni catalysts. An optimal Ni/ZrO catalyst affords an excellent low-temperature performance hitherto, with a CO conversion of 84.

Direct synthesis of urea from carbon dioxide and ammonia.

Urea is an essential fertilizer needed to meet the global demand for food. Currently, its production rate by reaction of carbon dioxide with ammonia is slow and the energy demand is high. Here we discuss strategies to overcome these challenges.

Using deep eutectic solvent dissolved low-value cotton linter based efficient magnetic adsorbents for heavy metal removal.

In this study, a novel magnetic bio-adsorbent was synthesized by modifying cotton linter (CL) cellulose with deep eutectic solvents (DESs) and FeO magnetic nanoparticles. The adsorption capacity of CL, FeO/CL, FeO/CL-oxidation, and FeO/CL-DES for Cu was 11.0, 66.

Emerging catalysts for the ambient synthesis of ethylene glycol from CO and its derivatives.

Ethylene glycol (EG), a useful chemical raw material, has been widely applied in many aspects of modern society. The conventional preparation of ethylene glycol mainly uses the petroleum route at high temperatures and pressure. More and more approaches have been developed to synthesize EG from CO and its derivatives under mild conditions.

Boosting Activity and Selectivity of UiO-66 through Acidity/Alkalinity Functionalization in Dimethyl Carbonate Catalysis.

The acid-base properties of supports have an enormous impact on catalytic reactions to regulate the selectivity and activity of supported catalysts. Herein, a train of Pd-X-UiO-66 (X = NO , NH , and CH ) catalysts with different acidity/alkalinity functional groups and encapsulated Pd(II) species is first developed, whose activities in dimethyl carbonate (DMC) catalysis are then investigated in details. Thereinto, the Pd-NO -UiO-66 catalyst with acidity functionalization exhibits the best catalytic behavior: the DMC selectivity stemmed from methyl nitrite (MN) is up to 68%, the conversion of CO is 73.

Chemical looping based ammonia production-A promising pathway for production of the noncarbon fuel.

Ammonia, primarily made with Haber-Bosch process developed in 1909 and winning two Nobel prizes, is a promising noncarbon fuel for preventing global warming of 1.5 °C above pre-industrial levels. However, the undesired characteristics of the process, including high carbon footprint, necessitate alternative ammonia synthesis methods, and among them is chemical looping ammonia production (CLAP) that uses nitrogen carrier materials and operates at atmospheric pressure with high product selectivity and energy efficiency.

Impact of preparation method on nickel speciation and methane dry reforming performance of Ni/SiO catalysts.

The methane dry reforming reaction can simultaneously convert two greenhouse gases (CH and CO), which has significantly environmental and economic benefits. Nickel-based catalysts have been widely used in methane dry reforming in past decade due to their low cost and high activity. However, the sintering and coke deposition of catalysts severely limit their industrial applications.

Emerging natural and tailored perovskite-type mixed oxides-based catalysts for CO conversions.

The rapid economic and societal development have led to unprecedented energy demand and consumption resulting in the harmful emission of pollutants. Hence, the conversion of greenhouse gases into valuable chemicals and fuels has become an urgent challenge for the scientific community. In recent decades, perovskite-type mixed oxide-based catalysts have attracted significant attention as efficient CO conversion catalysts due to the characteristics of both reversible oxygen storage capacity and stable structure compared to traditional oxide-supported catalysts.

Adsorption of Transition-Metal Clusters on Graphene and N-Doped Graphene: A DFT Study.

Using the dispersion-corrected density functional theory (DFT-D3) method, we systematically studied the adsorption of 15 kinds of transition-metal (TM) clusters on pristine graphene (Gr) and N-doped graphene (N-Gr). It has been found that TM ( = 1-4) clusters adsorbed on the N-Gr surface are much stronger than those on the pristine Gr surface, while 3d series clusters present similar geometries on Gr and N-Gr surfaces. The most preferred sites of TMs migrate from hollow to bridge to the top site on the Gr surface along the d series in the periodic table, while the preferred sites of TMs migrate in a much more complex manner on the N-Gr surface.

Boron Modified Bifunctional Cu/SiO Catalysts with Enhanced Metal Dispersion and Surface Acid Sites for Selective Hydrogenation of Dimethyl Oxalate to Ethylene Glycol and Ethanol.

Boron (B) promoter modified Cu/SiO bifunctional catalysts were synthesized by sol-gel method and used to produce ethylene glycol (EG) and ethanol (EtOH) through efficient hydrogenation of dimethyl oxalate (DMO). Experimental results showed that boron promoter could significantly improve the catalytic performance by improving the structural characteristics of the Cu/SiO catalysts. The optimized 2B-Cu/SiO catalyst exhibited excellent low temperature catalytic activity and long-term stability, maintaining the average EG selectivity (Sel.

Sustainable Carbon Materials toward Emerging Applications.

It is desirable for a sustainable society that the production and utilization of renewable materials are net-zero in terms of carbon emissions. Carbon materials with emerging applications in CO utilization, renewable energy storage and conversion, and biomedicine have attracted much attention both academically and industrially. However, the preparation process of some new carbon materials suffers from energy consumption and environmental pollution issues.

Robust nickel silicate catalysts with high Ni loading for CO methanation.

CO is the main component of greenhouse gases and also an important carbon source. The hydrogenation of CO to methane using Ni-based catalysts can not only alleviate CO emissions but also obtain useful fuels. However, Ni-based catalysts face one major problem of the sintering of Ni nanoparticles in the process of CO methanation.

Hollow Carbon Sphere Nanoreactors Loaded with PdCu Nanoparticles: Void-Confinement Effects in Liquid-Phase Hydrogenations.

Nanoreactors with hollow structures have attracted great interest in catalysis research due to their void-confinement effects. However, the challenge in unambiguously unraveling these confinement effects is to decouple them from other factors affecting catalysis. Here, we synthesize a pair of hollow carbon sphere (HCS) nanoreactors with presynthesized PdCu nanoparticles encapsulated inside of HCS (PdCu@HCS) and supported outside of HCS (PdCu/HCS), respectively, while keeping other structural features the same.

Mechanism and catalytic performance for direct dimethyl ether synthesis by CO hydrogenation over CuZnZr/ferrierite hybrid catalyst.

Direct synthesis of dimethyl ether (DME) by CO hydrogenation has been investigated over three hybrid catalysts prepared by different methods: co-precipitation, sol-gel, and solid grinding to produce mixed Cu, ZnO, ZrO catalysts that were physically mixed with a commercial ferrierite (FER) zeolite. The catalysts were characterized by N physisorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of CO (CO-TPD), temperature programmed desorption of NH (NH-TPD), and temperature programmed H reduction (H-TPR). The results demonstrate that smaller CuO and Cu crystallite sizes resulting in better dispersion of the active phases, higher surface area, and lower reduction temperature are all favorable for catalytic activity.

Engineering of Yolk/Core-Shell Structured Nanoreactors for Thermal Hydrogenations.

Heterogeneous hydrogenation reactions are of great importance for chemical upgrading and synthesis, but still face the challenges of controlling selectivity and long-term stability. To improve the catalytic performance, many hydrogenation reactions utilize special yolk/core-shell nanoreactors (YCSNs) with unique architectures and advantageous properties. This work presents the developmental and technological challenges in the preparation of YCSNs that are potentially useful for hydrogenation reactions, and provides a summary of the properties of these materials.

CO hydrogenation to high-value products via heterogeneous catalysis.

Recently, carbon dioxide capture and conversion, along with hydrogen from renewable resources, provide an alternative approach to synthesis of useful fuels and chemicals. People are increasingly interested in developing innovative carbon dioxide hydrogenation catalysts, and the pace of progress in this area is accelerating. Accordingly, this perspective presents current state of the art and outlook in synthesis of light olefins, dimethyl ether, liquid fuels, and alcohols through two leading hydrogenation mechanisms: methanol reaction and Fischer-Tropsch based carbon dioxide hydrogenation.