Ga-doped ZnO nanoparticles for enhanced CO gas sensing applications.

Gallium-doped zinc oxide (GZO) has demonstrated significant potential in gas-sensing applications due to its enhanced electrical and chemical properties. This study focuses on the synthesis, characterization, and gas-sensing performance of GZO nanoparticles (NPs), specifically targeting CO₂ detection, which is crucial for environmental monitoring and industrial safety. The GZO samples were synthesized using a sol-gel method, and their crystal structure was determined through X-ray diffraction (XRD), confirming the successful incorporation of gallium into the ZnO lattice.

Kinetic Insights into Methanol Synthesis from CO Hydrogenation at Atmospheric Pressure over Intermetallic PdGa Catalyst.

This study presents a single-site microkinetic model for methanol synthesis by CO hydrogenation over intermetallic PdGa/SiO. A reaction path analysis (RPA) combining theoretical results and realistic catalyst surface reaction data is established to elucidate the reaction mechanism and kinetic models of CO hydrogenation to methanol and CO. The RPA leads to the derivation of rate expressions for both reactions without presumptions about the most abundant reactive intermediate (MARI) and rate-determining step (rds).

Engaging the Concepts of Bimetallicity and Mechanical Strain for N Activation: A Computational Exploration.

N activation is a vital step in the process toward NH production. NH synthesis has been considered a crucial process for the production of value-added chemicals and/or hydrogen carriers over recent years. In this work, density functional theory (ab initio) calculations are implemented for a thorough screening of bimetallic alloy surfaces using Fe, Ru, and Mo as the matrix (host) metals and Ag, Au, Co, Cu, Fe, Mo, Ni, Pd, Pt, Rh, and Rh as heterometals toward exploring the N catalytic activation (electronic and chemical characteristics); the monometallic surfaces are used for critical comparison in terms of their N activation behavior.

Evolution of Oxygen Vacancy Sites in Ceria-Based High-Entropy Oxides and Their Role in N Activation.

In this work, a relatively new class of materials, rare earth (RE) based high entropy oxides (HEO) are discussed in terms of the evolution of the oxygen vacant sites (O) content in their structure as the composition changes from binary to HEO using both experimental and computational tools; the composition of HEO under focus is the CeLaPrSmGdO due to the importance of ceria-related (fluorite) materials to catalysis. To unveil key features of quinary HEO structure, ceria-based binary CePrO and CeLaO compositions as well as SiO, the latter as representative nonreducible oxide, were used and compared as supports for Ru (6 wt % loading). The role of the O in the HEO is highlighted for the ammonia production with particular emphasis on the N dissociation step (N → N) over a HEO; the latter step is considered the rate controlling one in the ammonia production.

Mid-temperature CO Adsorption over Different Alkaline Sorbents Dispersed over Mesoporous AlO.

CO adsorbents comprising various alkaline sorption active phases supported on mesoporous AlO were prepared. The materials were tested regarding their CO adsorption behavior in the mid-temperature range, i.e.

Synthesis, characterization, and preliminary insights of ZnFeO nanoparticles into potential applications, with a focus on gas sensing.

This work presents a hydrothermal-based facile method for synthesizing ZnFeO whose size can be controlled with the concentration of sodium acetate used as a fuel and its physical changes at nanoscales when exposed to two different gases. The structural, morphological, compositional, and electronic properties of the synthesized samples are also presented in this paper. The crystal structure of the synthesized samples was determined using an X-ray Diffractometer (XRD).

Crystallizing covalent organic frameworks from metal organic framework through chemical induced-phase engineering.

The ordered porous frameworks like MOFs and COFs are generally constructed using the monomers through distinctive metal-coordinated and covalent linkages. Meanwhile, the inter-structural transition between each class of these porous materials is an under-explored research area. However, such altered frameworks are expected to have exciting features compared to their pristine versions.

Salicylaldehydate coordinated two-dimensional-conjugated metal-organic frameworks.

A novel class of copper-based 2D-c-MOF was synthesized from 1,3,5-triformylphloroglucinol using green mechano-chemistry. Herein, metal coordination with the salicylaldehyde functional moiety was explored for the first time in MOFs. Moreover, an intrinsic semiconductive copper-based SA-MOF thin film was fabricated using an salt-free method at room temperature.

Carbon dioxide adsorbents from flame-made diesel soot nanoparticles.

Carbon dioxide (CO) is the top contributor to global warming. On the other, soot particles formed during fuel combustion and released into the atmosphere are harmful and also contribute to global warming. It would therefore be highly advantageous to capture soot and make use of it as a feedstock to synthesize carbon-based materials for applications such as carbon dioxide adsorption.

A Review on the Different Aspects and Challenges of the Dry Reforming of Methane (DRM) Reaction.

The dry reforming of methane (DRM) reaction is among the most popular catalytic reactions for the production of syngas (H/CO) with a H:CO ratio favorable for the Fischer-Tropsch reaction; this makes the DRM reaction important from an industrial perspective, as unlimited possibilities for production of valuable products are presented by the FT process. At the same time, simultaneously tackling two major contributors to the greenhouse effect (CH and CO) is an additional contribution of the DRM reaction. The main players in the DRM arena-Ni-supported catalysts-suffer from both coking and sintering, while the activation of the two reactants (CO and CH) through different approaches merits further exploration, opening new pathways for innovation.

Carbon Nanostructure/Zeolite Y Composites as Supports for Monometallic and Bimetallic Hydrocracking Catalysts.

In this study, we examine the effect of integrating different carbon nanostructures (carbon nanotubes, CNTs, graphene nanoplatelets, GNPs) into Ni- and Ni-W-based bi-functional catalysts for hydrocracking of heptane performed at 400 °C. The effect of varying the SiO2/Al2O3 ratio of the zeolite Y support (between 5 and 30) on the heptane conversion is also studied. The results show that the activity, in terms of heptane conversion, followed the order CNT/Ni-ZY5 (92%) > GNP/Ni-ZY5 (89%) > CNT/Ni-W-ZY30 (86%) > GNP/Ni-W-ZY30 (85%) > CNT/Ni-ZY30 (84%) > GNP/Ni-ZY30 (83%).

Decoupling the Chemical and Mechanical Strain Effect on Steering the CO Activation over CeO-Based Oxides: An Experimental and DFT Approach.

Doped ceria-based metal oxides are widely used as supports and stand-alone catalysts in reactions where CO is involved. Thus, it is important to understand how to tailor their CO adsorption behavior. In this work, steering the CO activation behavior of Ce-La-Cu-O ternary oxide surfaces through the combined effect of chemical and mechanical strain was thoroughly examined using both experimental and ab initio modeling approaches.

Polythiacalixarene-Embedded Gold Nanoparticles for Visible-Light-Driven Photocatalytic CO Reduction.

Metal nanoparticles are potent reaction catalysts, but they tend to aggregate, thereby limiting their catalytic efficiency. Their coordination with specific functional groups within a porous structure prevents their aggregation and facilitates the mass flow of catalytic starting materials and products. Herein, we use a thiacalix[4]arene-based polymer as a porous support with abundant docking sites for Au nanoparticles.

Transition Metal Phosphides (TMP) as a Versatile Class of Catalysts for the Hydrodeoxygenation Reaction (HDO) of Oil-Derived Compounds.

Hydrodeoxygenation (HDO) reaction is a route with much to offer in the conversion and upgrading of bio-oils into fuels; the latter can potentially replace fossil fuels. The catalyst's design and the feedstock play a critical role in the process metrics (activity, selectivity). Among the different classes of catalysts for the HDO reaction, the transition metal phosphides (TMP), e.

Solvent-Influenced Fragmentations in Free-Standing Three-Dimensional Covalent Organic Framework Membranes for Hydrophobicity Switching.

The ordered open organic frameworks membranes are attractive candidates for flow-assisted molecular separations. The physicochemical properties of such membranes mostly depend on their selectively chosen functional building blocks. In this work, we have introduced a novel concept of functional switchability of three-dimensional covalent organic framework (3D-COF) membranes through a simple solvent-influenced fragmentation method.

Functionalization of Biphenylcarbazole (CBP) with Siloxane-Hybrid Chains for Solvent-Free Liquid Materials.

We report herein the synthesis of siloxane-functionalized CBP molecules (4,4'-bis(carbazole)-1,1'-biphenyl) for liquid optoelectronic applications. The room-temperature liquid state is obtained through a convenient functionalization of the molecules with heptamethyltrisiloxane chains via hydrosilylation of alkenyl spacers. The synthesis comprises screening of metal-catalyzed methodologies to introduce alkenyl linkers into carbazoles (Stille and Suzuki Miyaura cross-couplings), incorporate the alkenylcarbazoles to dihalobiphenyls (Ullmann coupling), and finally introduce the siloxane chains.

Metal-Free Phosphated Mesoporous SiO as Catalyst for the Low-Temperature Conversion of SO to HS in Hydrogen.

Highly active metal-free mesoporous phosphated silica was synthesized by a two-step process and used as a SO hydrogenation catalyst. With the assistance of a microwave, MCM-41 was obtained within a 10 min heating process at 180 °C, then a low ratio of P precursor was incorporated into the mesoporous silica matrix by a phosphorization step, which was accomplished in oleylamine with trioctylphosphine at 350 °C for 2 h. For benchmarking, the SiO sample without P precursor insertion and the sample with P precursor insertion into the calcined SiO were also prepared.

Crystal and electronic facet analysis of ultrafine NiP particles by solid-state NMR nanocrystallography.

Structural and morphological control of crystalline nanoparticles is crucial in the field of heterogeneous catalysis and the development of "reaction specific" catalysts. To achieve this, colloidal chemistry methods are combined with ab initio calculations in order to define the reaction parameters, which drive chemical reactions to the desired crystal nucleation and growth path. Key in this procedure is the experimental verification of the predicted crystal facets and their corresponding electronic structure, which in case of nanostructured materials becomes extremely difficult.

CO Oxidation at Near-Ambient Temperatures over TiO-Supported Pd-Cu Catalysts: Promoting Effect of Pd-Cu Nanointerface and TiO Morphology.

Significant improvement of the catalytic activity of palladium-based catalysts toward carbon monoxide (CO) oxidation reaction has been achieved through alloying and using different support materials. This work demonstrates the promoting effects of the nanointerface and the morphological features of the support on the CO oxidation reaction using a Pd-Cu/TiO catalyst. Pd-Cu catalysts supported on TiO were synthesized with wet chemical approaches and their catalytic activities for CO oxidation reaction were evaluated.

Adsorption of Hydrogen Sulfide at Low Temperatures Using an Industrial Molecular Sieve: An Experimental and Theoretical Study.

In the work presented herein, a joint experimental and theoretical approach has been carried out to obtain an insight into the desulfurization performance of an industrial molecular sieve (IMS), resembling a zeolitic structure with a morphology of cubic crystallites and a high surface area of 590 m g, with a view to removing HS from biogas. The impact of temperature, HS inlet concentration, gas matrix, and regeneration cycles on the desulfurization performance of the IMS was thoroughly probed. The adsorption equilibrium, sorption kinetics, and thermodynamics were also examined.

Photocatalytic Degradation of Ethiofencarb by a Visible Light-Driven SnInS Photocatalyst.

This work reports the preparation and detailed characterization of stannum indium sulfide (SnInS) semiconductor photocatalyst for degradation of ethiofencarb (toxic insecticide) under visible-light irradiation. The as-prepared SnInS showed catalytic efficiency of 98% in 24 h under optimal operating conditions (pH = 3, catalyst dosage of 0.5 g L).

Design Aspects of Doped CeO for Low-Temperature Catalytic CO Oxidation: Transient Kinetics and DFT Approach.

CO elimination through oxidation over highly active and cost-effective catalysts is a way forward for many processes of industrial and environmental importance. In this study, doped CeO with transition metals (TM = Cu, Co, Mn, Fe, Ni, Zr, and Zn) at a level of 20 at. % was tested for CO oxidation.

Continuous selective deoxygenation of palm oil for renewable diesel production over Ni catalysts supported on AlO and LaO-AlO.

The present study provides, for the first time in the literature, a comparative assessment of the catalytic performance of Ni catalysts supported on γ-AlO and γ-AlO modified with LaO, in a continuous flow trickle bed reactor, for the selective deoxygenation of palm oil. The catalysts were prepared the wet impregnation method and were characterized, after calcination and/or reduction, by N adsorption/desorption, XRD, NH-TPD, CO-TPD, H-TPR, H-TPD, XPS and TEM, and after the time-on-stream tests, by TGA, TPO, Raman and TEM. Catalytic experiments were performed between 300-400 °C, at a constant pressure (30 bar) and different LHSV (1.

A DFT study of the adsorption energy and electronic interactions of the SO molecule on a CoP hydrotreating catalyst.

The adsorption energy and electronic properties of sulfur dioxide (SO) adsorbed on different low-Miller index cobalt phosphide (CoP) surfaces were examined using density functional theory (DFT). Different surface atomic terminations and initial molecular orientations were systematically investigated in detail to determine the most active and stable surface for use as a hydrotreating catalyst. It was found that the surface catalytic reactivity of CoP and its performance were highly sensitive to the crystal plane, where the surface orientation/termination had a remarkable impact on the interfacial chemical bonding and electronic states toward the adsorption of the SO molecule.

Nano-zerovalent manganese/biochar composite for the adsorptive and oxidative removal of Congo-red dye from aqueous solutions.

Congo-red (CR), a precursor of textile products and a contaminant of great concern, has contaminated aquatic environments. Here, we explored the synthesis of mesoporous nano-zerovalent manganese (nZVMn) and Phoenix dactylifera leaves biochar (PBC) composite for the removal of CR from water. The nZVMn/PBC adsorbed 117.