Manufacture Of Catalysts Research Articles

Facile synthesis of efficient pentaethylenehexamine-phosphotungstic acid heterogeneous catalysts for oxidative desulfurization

The ultra-deep desulfurization of oil needs to be solved urgently due to various problems, including environmental pollution and environmental protection requirements. Oxidative desulfurization (ODS) was considered to be the most promising technology. The facile synthesis of highly efficient and stable HPW-based heterogeneous catalysts for oxidative desulfurization is still a challenging task. In this paper, pentamethylene hexamine (PEHA) and phosphotungstic acid (HPW) were combined by a simple one-step method to prepare a heterogeneous catalyst of PEHA-HPW for the production of ultra-deep desulfurization fuel oil. The composite material exhibited excellent catalytic activity and high recyclability, which could reach a 100% dibenzothiophene (DBT) removal rate in 30 min and be recycled at least 5 times. Experiments and DFT simulations were used to better examine the ODS mechanism of PEHA-HPW. It was proved that the rich amino groups on the surface of PEHA-HPW play a crucial role. This work provides a simple and feasible way for the manufacture of efficient HPW-based catalysts.

Thermomechanical Responses of Microcracks in a Honeycomb Particulate Filter

Manufacturing honeycomb‐structured catalysts require a careful understanding of the microstructure of the solid substrate and its dependence on thermal‐processing conditions. Herein, it is the thermal responses of microcracks in an uncoated microcracked aluminum titanate honeycomb catalyst is investigated by analyzing the material's resonance frequency using the high‐temperature impulse excitation technique. The resonance frequencies are presented as Young's modulus values to avoid sample size effects. Dynamic Young's modulus measurements show closed‐loop hysteresis due to microcracks healing and reopening, causing a reversible response. The hysteresis is further used to understand microcracks’ dependence on critical thermal‐processing conditions used in a catalyst manufacturing plant, including peak operating temperature (800–1000 °C), dwell period (1–3 h), and heating rates (1–5 °C min−1). Microcracks are observed to have two healing responses: instantaneous and delayed healing. Both responses significantly influence the design of catalyst manufacturing. Complete reopening of microcracks from their healing temperature (1150 °C) is a very time‐consuming process (50–60 h). However, it is shown in the analysis that microcrack relaxation is a critical phenomenon that must be considered in quality‐controlled environments.

Atomically Dispersed NiNx Site with High Oxygen Electrocatalysis Performance Facilely Produced via a Surface Immobilization Strategy

Nonprecious-metal heterogeneous catalysts with atomically dispersed active sites demonstrated high activity and selectivity in different reactions, and the rational design and large-scale preparation of such catalysts are of great interest but remain a huge challenge. Current approaches usually involve extremely high-temperature and tedious procedures. Here, we demonstrated a straightforward and scalable preparation strategy. In two simple steps, the atomically dispersed Ni electrocatalyst can be synthesized in a tens grams scale with quantitative yield under mild conditions, and the active Ni sites were produced by immobilizing preorganized NiNx complex on the substrate surface via organic thermal reactions. This catalyst exhibits excellent catalysis performances in both oxygen evolution and reduction reactions. It also exhibited tunable catalysis activity, high catalysis reproducibility, and high stability. The atomically dispersed NiNx sites are tolerant at high Ni concentration, as the random reactions and metal nanoparticle formation that generally occurred at high temperatures were avoided. This strategy illustrated a practical and green method for the industrial manufacture of nonprecious-metal single-site catalysts with a predictable structure.

UiO-66 MOF-Derived Ru@ZrO2 Catalysts for Photo-Thermal CO2 Hydrogenation

The use of metal–organic frameworks (MOFs) as templates or precursors in the manufacture of heterogeneous catalysts is highly attractive due to the transfer of MOFs’ inherent porosity and homogeneous metallic distribution to the derived structure. Herein, we report on the preparation of MOF-derived Ru@ZrO2 catalysts by controlled thermal treatment of zirconium-based MOF UiO-66 with ruthenium moieties. Ru3+ (3 or 10 mol%) precursor was added to UiO-66 synthesis and, subsequently, the as-synthesized hybrid structure was calcined in flowing air at different temperatures (400–600 °C) to obtain ZrO2-derived oxides doped with highly dispersed Ru metallic clusters. The materials were tested for the catalytic photo-thermal conversion of CO2 to CH4. Methanation experiments were conducted in a continuous flow (feed flow rate of 5 sccm and 1:4 CO2 to H2 molar ratio) reactor at temperatures from 80 to 300 °C. Ru0.10@ZrO2 catalyst calcined at 600 °C was able to hydrogenate CO2 to CH4 with production rates up to 65 mmolCH4·gcat.–1·h–1, CH4 yield of 80% and nearly 100% selectivity at 300 °C. The effect of the illumination was investigated with this catalyst using a high-power visible LED. A CO2 conversion enhancement from 18% to 38% was measured when 24 sun of visible LED radiation was applied, mainly due to the increase in the temperature as a result of the efficient absorption of the radiation received. MOF-derived Ru@ZrO2 catalysts have resulted to be noticeably active materials for the photo-thermal hydrogenation of CO2 for the purpose of the production of carbon-neutral methane. A remarkable effect of the ZrO2 crystalline phase on the CH4 selectivity has been found, with monoclinic zirconia being much more selective to CH4 than its cubic allotrope.

Single-atom Pt-CeO2/Co3O4 catalyst with ultra-low Pt loading and high performance for toluene removal

The design and manufacture of high activity and thermal stability catalysts with minimal precious metal loading is essential for deep degradation of volatile organic compounds (VOCs). In this paper, a novel single-atom Pt-CeO2/Co3O4 catalyst with ultra-low Pt loading capacity (0.06 wt%, denoted as 0.06Pt-SA) was fabricated via one-step co-precipitation method. The 0.06Pt-SA exhibited excellent toluene degradation activity of T90 = 169 °C, matched with the nanoparticle Pt-supported CeO2/Co3O4 catalyst with more than six times higher Pt loading (0.41 wt%, denoted as 0.41Pt-NP). Moreover, the ultra-long durability (toluene conversion remains 99% after 120 h stability test) and excellent toluene degradation ability in a wide space speed range of 0.06Pt-SA were superior to that of 0.41Pt-NP catalyst. The excellent performance was derived from the strong metal-support interaction (SMSI) between the single atomic Pt and the carrier, which induced more Pt0 and Ce3+ for oxygen activation and more Co3+ for toluene removal. The in situdiffuse reflectance infrared spectroscopy (DRIFTS) experiments confirmed that the conversion of intermediates was accelerated in the reaction process, thereby promoting the toluene degradation. Our results should inspire the exploitation of noble single-atomic modification strategy for developing the low cost and high performance VOCs catalyst.

Sustainable utilization of palladium from industrial catalytic waste by a smart magnetic nano stirring robot

The rapid and accurate recovery of precious metal palladium from waste resources has always been a hot and challenging topic. In addition, from the perspective of energy and environmental protection, the regeneration and rational use of waste are also crucial for a sustainable future. Here, an 8-aminoquinoline-modified core–shell magnetic nano stirring robot (MNSR@PGMA-AQ) towards Pd(Ⅱ) is reported which not only has ultra-high solid–liquid separation efficiency but also can accelerate the mass transfer rate in adsorption through self-stirring. A series of adsorption experiments show that MNSR@PGMA-AQ has fast adsorption kinetics, reaching 10.97 mg g−1 in 20 min, which is 85.87 % of the equilibrium adsorption capacity. And selectivity parameters such as distribution coefficient (KD), separation factor (α) and concentration factor (CF) demonstrate its excellent adsorption selectivity for Pd(Ⅱ). Moreover, it is proved that the adsorption mechanism of MNSR@PGMA-AQ towards Pd(Ⅱ) is ion exchange and chelation, which mainly depends on the functional monomer 8-aminoquinoline. The regeneration and palladium recovery experiments in actual samples further prove the application value of this novel robot. Furthermore, Pd-loaded MNSR@PGMA-AQ was used as a catalyst for the Suzuki-Miyaura cross-coupling reaction and investigated its catalytic performance to pursue the goal of waste regeneration and responsible catalyst manufacture.

American Elements expands organometallic compounds production to meet demand from thin film and catalyst manufacturers

American Elements expands organometallic compounds production to meet demand from thin film and catalyst manufacturers

Controlled Manufacture of Heterogeneous Catalysts for the Hydrogenation of CO2 via Steam Pyrolysis of Different Metal–Organic Frameworks

The use of metal–organic frameworks (MOFs) as precursors for the manufacture of heterogeneous catalysts has gained a great deal of attention over the last decade. By subjecting a given MOF to pyrolysis, electrochemical degradation, or other treatments under a controlled atmosphere, (supported) metal (oxide) nanoparticles with very narrow size distributions can be obtained, opening the door to the design of more efficient catalytic solids. Here, we demonstrate the benefits of steam during the controlled decomposition of two different MOF structures (Basolite F300(Fe) and In@ZIF-67(Co)) and the consequences of treatment under this mildly oxidizing atmosphere on the properties of the resulting catalysts for the direct hydrogenation of CO2 to hydrocarbons and methanol. In-depth characterization demonstrates that steam addition helps to control the phase composition both before and after catalysis; additionally, it results in the formation of smaller nanoparticles, thus leading to more efficient catalysts in comparison with conventional pyrolysis.

Highly Efficient Synthesis of Imidazolecarboxylate Salts via Sequential Nucleophilic Addition-Intramolecular Cyclization Reactions

Abstract: In this work, we used a highly efficient and easy approach for synthesizing imidazolecarboxylate salt through the reaction between α-amidino carboxylic acids and α-halo ketones with as readily available starting materials in the presence of KHCO3 at THF under reflux. Targeted synthesis of this type of imidazole bearing the carboxylic acid group in a single structure, in addition to the biological properties enriched as a ligand, is very popular in the manufacture of catalysts. The salient features of this protocol include eco-friendly, high atom-economical, easy and mild conditions that led to the production of all products with high yields. Furthermore, all products were purified without the need for column chromatography through the GAP chemistry (group-assisted purification chemistry) technique.

Strain engineering of electrocatalysts for hydrogen evolution reaction.

As the key half reaction of water-splitting electrolysis, the hydrogen evolution reaction (HER) that occurs at the cathode directly determines the overall efficiency of hydrogen production. To improve the efficiency of electrochemical water splitting for hydrogen generation, efficient and robust catalysts need to be developed. Strain engineering, which represents an effective and promising category of strategies, can regulate the electronic structures of catalysts by modulating the lattice strain and ultimately optimizing the HER dynamics. This work critically reviews the recent progress of strain engineering in HER and provides future perspectives for this area. The methods and characterization techniques are also introduced in detail. Hopefully this review can provide guidelines for the design and manufacturing of advanced catalysts for HER and other heterogeneous catalysis reactions such as chemical sensing, CO2 reduction and NH3 synthesis.

STRUCTURE AND PHYSICAL-MECHANICAL PROPERTIES OF ELECTROCRYSTALLISED COATINGS OF Ni−P ALLOY

The purpose of the research. Ni−P electrolytic alloy coated products are of great interest in many industries such as electronics (magnetic recording devices), oil and gas industry, medical equipment manufacturing, catalyst manufacturing. In this connection, the task of determining rational deposition modes of electrocrystallized coatings based on Ni−P alloy with increased technological and operational properties and researching their structure arises. In addition, there is a need to replace chrome electrocoatings, which, along with very high indicators of mechanical, protective and decorative properties, are obtained from toxic electrolytes that are dangerous of human life and health. Materials and methodology. In this work, electroplating of Ni−P alloy, obtained from a new electrolyte developed by us, was proposed as a replacement for chromium. Modes of obtaining high-quality electrocoating with Ni−P alloy have been identified, in which the best deposition characteristics, mechanical and decorative properties have been determined. Results. The effect of electrolysis parameters on current output, deposition rate, microhardness, surface morphology and reflectivity of electrocrystallized coatings was investigated. It was also found that the addition of phosphorus ions to the nickel plating electrolyte leads to amorphization of Ni−P alloy deposits. Scientific novelty. The influence of the deposition regime on the formation of the internal structure and surface morphology of Ni−P electrolytic coatings obtained from the electrolyte developed by the authors was studied. Conclusions. The patterns of electrodeposition of Ni−P alloy coatings were studied, and the factors influencing the formation of structure and properties were identified. It was established that the addition of phosphorus ions to the nickel plating electrolyte leads to amorphization of coatings, an increase in microhardness and reflectivity. On the basis of the analysis of the received data, the optimal conditions of electrocrystallization, under which it is possible to obtain a coating with specified physical and mechanical properties, are determined.

Toward sustainability in zeolite manufacturing: An industry perspective.

Conventional zeolite manufacturing processes are highly energy-intensive and come along with a significant carbon dioxide footprint. Here, we discuss the main energy consumers and potential alternatives toward a more sustainable production of zeolites: from simple optimization efforts on existing unit operations to new and novel manufacturing concepts such as the continuous crystallization and solidothermal route toward zeolites and their industrial applicability. These efforts contribute to the global effort into transitioning manufacturing of chemicals and catalysts to a net-zero environment by cutting greenhouse gas emissions to as close to zero as possible.

Characteristics of Heterogeneous Catalysts Fly Ash Fraction of Light Shell and Fiber of Palm Oil Mill Solid Waste Grown on Peatlands

Utilization of biomass from agricultural waste in Indonesia is still not optimal. Biomass from agricultural waste containing of Si and Ca can be used for the manufacture of heterogeneous base catalysts. The catalyst produced will be applied to the manufacture of biodiesel. A biodiesel quality test and Gas chromatography-mass spectroscopy (GC-MS) test are carried out, including chemical composition analysis test (X-RD), three-dimensional structure (SEM), material characterization (FT-IR), surface and basic properties (BET), and mass-weight change (TGA). The research method used is an experimental method, where this research was carried out in 3 stages; the first stage is to determine the test and characteristics of crude palm oil raw material, the second is on the manufacture of palm ash catalyst, and the third is the application of a heterogeneous catalyst based on palm fly ash in the manufacture of biodiesel. The results on the characteristics of crude palm oil after purification using 5% shell activated charcoal showed an increase in quality, including the number of free fatty acids 3.86% w/w, water content 0.0015%, impurities content 0.0485%. The acid number of 13.840mgKOH/g is still within the quality standard, while for the quality of the biodiesel produced, the calcination catalyst treatment at a temperature of 700ºC for 5 hours for the density parameter is 0.860g/ml, water content is 0.03%-wb, iodine number is 26.30gI2/100g, saponification number 90.88mgKOH/g, and free fatty acid number 0.38%w/w have values according to biodiesel standard ASTM D6751. Catalyst calcined at 700ºC 5 hours found mesopore (7.93 nm) with a surface area 25.288 m²/g. It also has CaO around 36º peaks, where catalyst particles are spherical with a smooth surface.

V2O5-WO3 catalysts treated with titanium isopropoxide using a one-step co-precipitation method for selective catalytic reduction with NH3

Selective Catalytic Reduction (SCR) of nitrogen oxides (NOx) is the most effective way to reduce NOx emissions. However, the most used catalysts for this purpose, V2O5-WO3/TiO2 (VWTi) hybrid system, have limited applicability owing to its narrow operating temperature range (300–400 °C). Therefore, catalysts with abundant active sites are needed to extend the temperature range to more acceptable values (200–400 °C). The number of active sites depends on the catalyst synthesis method. The aim of this study is to increase the dispersion of V-OH and W-OH through a one-step process, this is achieved by treating the TiO2 support with titanium isopropoxide (TTIP) and simultaneously incorporating the V-OH and W-OH. This synthesis method used here is expected to enhance the interaction between the support and V-OH and W-OH by increasing the number of catalytically active sites. This process is simple and could be applied for the catalyst manufacturing process in the industrial scale. The optimal performance observed for the catalysts prepared at a TTIP loading of 5 wt% using a one-step method is due to its higher catalytic activity at lower temperatures, the observed results could be explained based on the formation of abundant V-OH and W-OH functional groups and the V4+/V5+ ratio (≈1). The scope of this study is to develop a new catalyst for selective catalytic reduction of nitrogen oxides.

Examples, Perspectives, and Impact of in-Operando Electrochemistry & Electrodeposition

In order to leave our children not with a huge problem in the future, we quickly have to realize the energy transition to renewable and CO2 neutral sources and circuits, which implies the introduction of the complete H2 economy. In addition, the ever ongoing demand and progress in electronics requires new and smart steps from the semiconducting industry pushing the border for device fabrication and thus material science and nanotechnology.Both extremely important topics crucially depend on the complete understanding of the fundamental atomic processes for device or catalyst manufacturing by electrodeposition as well as their stability during operation under (electrochemical) application.The general problem, however, has been formulated nicely already by Wolfgang Pauli:„God made the bulk; surfaces were invented by the devil.“It took around two decades, before most of the basic concepts and atomic effects have been observed and understood in standard, ultra-high vacuum (UHV) surface science and nanotechnology. Now, it is surely time to open a similar book and start from scratch, as atoms and surfaces in electrochemical environment clearly behave differently than in UHV. Moreover, this time it is not enough to measure after the deposition, after the growth, after the nucleation, or after a reaction!Both electrochemical data clearly show that many surfaces change during application and the complex understanding during electrodepostion, which involves a huge parameter space of tunable variables, can surely only be addressed adequately by in operando measurements.In this talk, I will show examples from in operando measurements ranging from STM over TEM to SXRD and X-ray photoelectron spectroscopy that all demonstrate the power and perspective for gaining new insight. Figure 1

Electrochemical Metal Recycling: Recovery of Palladium from Solution and In Situ Fabrication of Palladium-Carbon Catalysts via Impact Electrochemistry.

Recycling of critical materials, regeneration of waste, and responsible catalyst manufacture have been repeatedly documented as essential for a sustainable future with respect to the environment and energy production. Electrochemical methods have become increasingly recognized as capable of achieving these goals, and “impact” electrochemistry, with the advantages associated with dynamic nanoelectrodes, has recently emerged as a prime candidate for the recovery of metals from solution. In this report, the nanoimpact technique is used to generate carbon-supported palladium catalysts from low-concentration palladium(II) chloride solutions (i.e., a waste stream mimic) as a proof of concept. Subsequently, the catalytic properties of this material in both synthesis (Suzuki coupling reaction) and electrocatalysis (hydrogen evolution) are demonstrated. Transient reductive impact signals are shown and analyzed at potentials negative of +0.4 V (vs SCE) corresponding to the onset of palladium deposition in traditional voltammetry. Direct evidence of Pd modification was obtained through characterization by environmental scanning electron microscopy/energy-dispersive X-ray spectroscopy, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, transmission electron microscopy, and thermogravimetric analysis of impacted particles. This showed the formation of deposits of Pd0 partially covering the 50 nm carbon black particles with approximately 14% Pd (wt %) under the conditions used. This material was then used to demonstrate the conversion of iodobenzene into its biphenyl product (confirmed through nuclear magnetic resonance) and the successful production of hydrogen as an electrocatalyst under acidic conditions (under cyclic voltammetry).

Photoreactor-Initiated Acetaldehyde Conversion Rate of a TiO2-Surface-Treated Alumina Photocatalyst Prepared Using the Sol–Gel Method

In this study, a TiO2–alumina photocatalyst was manufactured by coating a surface-treated alumina substrate with TiO2 sol using the sol–gel method, and the photolysis and conversion of acetaldehyde in the gas phase were evaluated. The effects of acetaldehyde flow rate (i.e., retention time), ultraviolet wavelength, moisture, and catalyst heat-treatment temperature on the conversion of acetaldehyde were investigated. The experiments confirmed that a decrease in flow rate (i.e., increase in retention time), increase in moisture level, and decrease in the ultraviolet wavelength of the light source increased the conversion rate of the gaseous acetaldehyde. Among the three heat-treatment temperatures (450, 650, and 850 °C) used in the catalyst manufacturing process, the catalyst treated at 650 °C had the highest acetaldehyde conversion rate. As a result of its increased acetaldehyde decomposition and photoefficiency, the newly manufactured TiO2–alumina photocatalyst is expected to be used alongside a photoreactor as an air-purifying filter. Furthermore, the photocatalyst surface treatment demonstrated herein can be adopted to fabricate various environmentally friendly materials in the future.

The Importance of Recovery of PGMS from Catalysts – A Case Study of Recycling Network in Poland

Abstract Combustion engines are the main driving force of passenger cars, trucks or buses. Engines burn fuels, and as a side effect, release many pollutions to the atmosphere. Car manufacturers had been aware of a need of lowering the amount of exhaust fumes. This brought on the market the first catalytic converters. Nowadays automobile catalyst manufacturing is the largest sector of demand of PGMs (mainly platinum, palladium and rhodium), and unfortunately consumption and future demand of there critical metals is getting higher. Over the past two decades, most countries around the world have developed and implement solutions that would minimize the impact of the growing number of cars on the environment. One solution contributing to this is the organisation of an end-of-life car collection and recycling network, which is now an integral part of automotive industry. The main drivers for the development of such network were stricter environmental regulations and economic conditions. The development of recycling is also becoming more popular in Poland. However, catalyst recycling system is still not transparent to all stakeholders. Due to the huge variety of catalysts and their different structure and composition of elements from the PGMs group, the valuation of their price before they are recycled is not obvious. This raises a lot of controversy and does not inspire trust among those who recycle their catalysts. The aim of this work is to show how the management of used catalytic converters looks like in Poland and how developed is network of catalysts recycling in Poland. At the same time this will show how important it is in terms of a circular economy and the recovery of valuable raw materials from a group of PGMs.

Oxy-Anionic Doping: A New Strategy for Improving Selectivity of Ru/CeO2 with Synergetic Versatility and Thermal Stability for Catalytic Oxidation of Chlorinated Volatile Organic Compounds.

Understanding the formation and inhibition of more toxic polychlorinated byproducts from the catalytic oxidation elimination of chlorinated volatile organic compounds (Cl-VOCs) and unveiling efficient strategies have been essential and challenging. Here, RuOx supported on CePO4-doped CeO2 nanosheets (Ru/Pi-CeO2) is designed for boosting catalytic oxidation for the removal of dichloromethane (DCM) as a representative Cl-VOC. The promoted acid strength/number and sintering resistance due to the doping of electron-rich and thermally stable CePO4 are observed along with the undescended redox ability and the exposed multi-active sites, which demonstrates a high activity and durability of DCM oxidation (4000 mg/m3 and 15,000 mL/g·h, stable complete-oxidation at 300 °C), exceptional versatility for different Cl-VOCs, alkanes, aromatics, N-containing VOCs, CO and their multicomponent VOCs, and enhanced thermal stability. The suppression of polychlorinated byproducts is determined over Ru/Pi-CeO2 and oxy-anionic S, V, Mo, Nb, or W doping CeO2, thus the oxy-anionic doping strategy is proposed based on the quenching of the electron-rich oxy-anions on chlorine radicals. Moreover, the simple mechanical mixing with these oxy-anionic salts is also workable even for other catalysts such as Co, Sn, Mn, and noble metal-based catalysts. This work offers further insights into the inhibition of polychlorinated byproducts and contributes to the convenient manufacture of monolithic catalysts with superior chlorine-poisoning resistance for the catalytic oxidation of Cl-VOCs.

Early-stage evaluation of catalyst manufacturing cost and environmental impact using CatCost

Early-stage evaluation of catalyst manufacturing cost and environmental impact using CatCost