scholarly journals First of Its Kind Automotive Catalyst Prepared by Recycled PGMs-Catalytic Performance

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 942
Author(s):  
Anastasia Maria Moschovi ◽  
Mattia Giuliano ◽  
Marios Kourtelesis ◽  
Giovanna Nicol ◽  
Ekaterini Polyzou ◽  
...  
Keyword(s):  
Oxygen Storage Capacity ◽  
Catalytic Performance ◽  
Platinum Group Metals ◽  
Oxygen Storage ◽  
Small Scale ◽  
Gas Mixture ◽  
Oxidation Reactions ◽  
Fresh Catalyst ◽  
Metal Precursors ◽  
Automotive Catalytic Converters

The production of new automotive catalytic converters requires the increase of the quantity of Platinum Group Metals in order to deal with the strict emission standards that are imposed for vehicles. The use of PGMs coming from the recycling of spent autocatalysts could greatly reduce the cost of catalyst production for the automotive industry. This paper presents the synthesis of novel automotive Three-Way Catalysts (PLTWC, Pd/Rh = 55/5, 60 gPGMs/ft3) and diesel oxidation catalysts (PLDOC, Pt/Pd = 3/1, 110 gPGMs/ft3) from recovered PGMs, without further refinement steps. The catalysts were characterized and evaluated in terms of activity in comparison with benchmark catalysts produced using commercial metal precursors. The small-scale catalytic monoliths were successfully synthesized as evidenced by the characterization of the samples with XRF analysis, optical microscopy, and N2 physisorption. Hydrothermal ageing of the catalysts was performed and led to a significant decrease of the specific surface area of all catalysts (recycled and benchmarks) due to sintering of the support material and metal particles. The TWCs were studied for their activity in CO and unburned hydrocarbon oxidation reactions under a slightly lean environment of the gas mixture (λ > 1) as well as for their ability to reduce NOx under a slightly rich gas mixture (λ < 1). Recycled TWC fresh catalyst presented the best performance amongst the catalysts studied for the abatement of all pollutant gases, and they also showed the highest Oxygen Storage Capacity value. Moreover, comparing the aged samples, the catalyst produced from recycled PGMs presented higher activity than the one synthesized with the use of commercial PGM metal precursors. The results obtained for the DOC catalysts showed that the aged PLDOC catalyst outperformed both the fresh catalyst and the aged DOC catalyst prepared with the use of commercial metal precursors for the oxidation of CO, hydrocarbons, and NO. The latter reveals the effect of the presence of several impurities in the recovered PGMs solutions.

High oxygen storage capacity and enhanced catalytic performance of NiO/NixCe1−xO2−δ nanorods: synergy between Ni-doping and 1D morphology

RSC Advances ◽  
2015 ◽  
Vol 5 (67) ◽  
pp. 54571-54579 ◽  
Author(s):  
Araceli Romero-Núñez ◽  
Gabriela Díaz
Keyword(s):  
Storage Capacity ◽  
Chemical Properties ◽  
Oxygen Storage Capacity ◽  
Catalytic Performance ◽  
Oxygen Storage ◽  
Doped Ceria ◽  
Ni Doping ◽  
Specific Composition ◽  
Physical Chemical ◽  
High Oxygen Storage Capacity

NiO/Ni-doped ceria nanorods have been synthesized. Their unique structure combines specific composition and 1D morphology, which provide great improvements in their physical chemical properties.

scholarly journals PROMETHEUS: A Copper-Based Polymetallic Catalyst for Automotive Applications. Part I: Synthesis and Characterization

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 622
Author(s):  
Iakovos Yakoumis
Keyword(s):  
Large Scale ◽  
Catalytic Performance ◽  
Platinum Group Metals ◽  
Oxygen Storage ◽  
Molar Ratio ◽  
High Catalytic Activity ◽  
Impregnation Method ◽  
X Ray ◽  
Heterogeneous Catalytic ◽  
Nano Catalyst

According to the strict European exhaust emissions standards that have been imposed by European legislation there is an elevated need for the decrease of the toxic gas emissions from vehicles. Therefore, car manufacturers have implemented a series of catalytic devices in the aftertreatment of the engine to comply with the standards. All catalytic devices (such as three-way catalysts, diesel particulate filters and diesel oxidation catalysts) accumulate concentrated loading of platinum group metals (PGMs, platinum, palladium, rhodium) as the active catalytic phase. Thus, the demand for PGMs is constantly increasing with a subsequent increase in their market prices. As a result, the research on catalytic converters of high activity and reduced cost/PGM loading is of great interest. In the present work, the Prometheus catalyst, a polymetallic nanosized copper-based catalyst for automotive emission control applications, is presented in two different metal loadings (2 wt% and 5 wt%) and metal ratios (Cu/Pd/Rh = 21/7/1 and Cu/Pd/Rh = 21/7/3). For the first time, a three-metal (copper, palladium, rhodium) nano-catalyst has been synthesized and characterized on a large scale. By using copper as an active catalytic phase, a reduction of PGMs loading is achieved (up to 85%) resulting in a novel catalytic device with similar or improved catalytic performance compared to commercial ones. The Prometheus catalyst is prepared by a wet impregnation method, using as a carrier an inorganic mixed oxide (CeZrO4) exhibiting elevated oxygen storage capacity (OSC). The heterogeneous catalytic powders produced were characterized by both spectroscopic and analytical methods. The metal content and ratio were determined by inductively coupled plasma mass spectrometry (ICP-MS), X-ray fluorescence (XRF) and energy-dispersive X-ray spectroscopy (EDS). The morphology and the catalyst particle size were determined with scanning electron microscopy (SEM) and X-ray diffraction (XRD). The investigation revealed homogeneous particle formation and dispersion. The deposition of the metal nanoparticles on the porous inorganic carrier was verified with N2 sorption. Catalytic performance and reactivity of a catalyst (pure wash coat) with molar ratio 21/7/1 and a full-scale Prometheus catalyst with the desired loading of 15 g/ft3 were tested on an in-house synthetic gas bench (SGB) for the abatement of CO, CH4 and NO, both presenting high catalytic activity.

scholarly journals Praseodymium-Doped Ce0.5Co0.5O2 Catalyst for Use on the Ethanol Steam Reforming to Produce Hydrogen

2016 ◽  
Vol 66 ◽  
pp. 13-24
Author(s):  
Ya Ping Chen ◽  
Chen Lung Chuang ◽  
Pei Di Jeng ◽  
Ruei Ci Wu ◽  
Chen Bin Wang
Keyword(s):  
Steam Reforming ◽  
Oxygen Storage Capacity ◽  
Catalytic Performance ◽  
Oxygen Storage ◽  
Ethanol Conversion ◽  
Ethanol Steam Reforming ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Hydrogen Distribution ◽  
Ethanol Steam

The catalytic performance of ethanol steam reforming (ESR) reaction was investigated on a praseodymium (Pr) dopant to modify Ce0.5Co0.5O2catalyst. The Ce0.5Co0.5O2catalyst was prepared by co-precipitation-oxidation method with NaOH precipitant and H2O2oxidant. Doped 5 and 10 wt% Pr (Pr5-Ce-Co and Pr10-Ce-Co) catalysts were prepared by an incipient wetness impregnation method and reduced at 250 and 400 °C (H250 and H400). All samples were characterized by using XRD, TPR, BET, EA, TG and TEM techniques at various stages of the catalyst. The results indicated that the doped Pr improved the activity and products distribution, and depressed the deposited carbon. The Pr10-Ce-Co-H400 sample was a highly active and stable among these catalysts, where the hydrogen distribution approached 72% at 475 °C and only minor C1(CO and CH4) species were detected. In addition, the ethanol conversion still remained complete, and the selectivity of hydrogen exceeded 70% during a 100 h time-on-stream test at 400 °C. The high oxygen storage capacity (OSC) and high accessible oxygen for this catalyst allowed oxidation/gasification of deposited carbon as soon as it formed, and less coke was detected.

Key properties of Ni–MgO–CeO2, Ni–MgO–ZrO2, and Ni–MgO–Ce(1−x)Zr(x)O2catalysts for the reforming of methane with carbon dioxide

2018 ◽  
Vol 20 (7) ◽  
pp. 1621-1633 ◽  
Author(s):  
Won-Jun Jang ◽  
Hak-Min Kim ◽  
Jae-Oh Shim ◽  
Seong-Yeun Yoo ◽  
Kyung-Won Jeon ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Storage Capacity ◽  
Oxygen Storage Capacity ◽  
Catalytic Performance ◽  
Oxygen Storage ◽  
Key Factors

The size of Ni particles and the oxygen storage capacity are found to be the primary and secondary key factors that influence the catalytic performance, respectively.

Oxygen storage capacity versus catalytic activity of ceria–zirconia solid solutions in CO and HCl oxidation

2019 ◽  
Vol 9 (9) ◽  
pp. 2163-2172 ◽  
Author(s):  
Yu Sun ◽  
Chenwei Li ◽  
Igor Djerdj ◽  
Omeir Khalid ◽  
Pascal Cop ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Solid Solutions ◽  
Storage Capacity ◽  
Oxygen Storage Capacity ◽  
Oxygen Storage ◽  
Oxidation Reactions ◽  
The Relationship

CexZr1−xO2 solid solutions were prepared to explore the relationship between oxygen storage capacity and activity of oxidation reactions.

scholarly journals Recent Advances in MnOx/CeO2-Based Ternary Composites for Selective Catalytic Reduction of NOx by NH3: A Review

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1519
Author(s):  
Hao Sun ◽  
Soo-Jin Park
Keyword(s):  
Selective Catalytic Reduction ◽  
Manganese Oxides ◽  
Separation Efficiency ◽  
Catalytic Reduction ◽  
Relevant Literature ◽  
Oxygen Storage Capacity ◽  
Catalytic Performance ◽  
Oxygen Storage ◽  
Application Process ◽  
Intimate Contact

Recently, manganese oxides (MnOx)/cerium(IV) oxide (CeO2) composites have attracted widespread attention for the selective catalytic reduction (SCR) of nitrogen oxides (NOx) with ammonia (NH3), which exhibit outstanding catalytic performance owing to unique features, such as a large oxygen storage capacity, excellent low-temperature activity, and strong mechanical strength. The intimate contact between the components can effectively accelerate the charge transfer to enhance the electron–hole separation efficiency. Nevertheless, MnOx/CeO2 still reveals some deficiencies in the practical application process because of poor thermal stability, and a low reduction efficiency. Constructing MnOx/CeO2 with other semiconductors is the most effective strategy to further improve catalytic performance. In this article, we discuss progress in the field of MnOx/CeO2-based ternary composites with an emphasis on the SCR of NOx by NH3. Recent progress in their fabrication and application, including suitable examples from the relevant literature, are analyzed and summarized. In addition, the interaction mechanisms between MnOx/CeO2 catalysts and NOx pollutants are comprehensively dissected. Finally, the review provides basic insights into prospects and challenges for the advancement of MnOx/CeO2-based ternary catalysts.

scholarly journals Effect of support oxygen storage capacity on the catalytic performance of Rh nanoparticles for CO2 reforming of methane

2019 ◽  
Vol 243 ◽  
pp. 490-501 ◽  
Author(s):  
Ioannis V. Yentekakis ◽  
Grammatiki Goula ◽  
Maria Hatzisymeon ◽  
Ioanna Betsi-Argyropoulou ◽  
Georgia Botzolaki ◽  
...  
Keyword(s):  
Storage Capacity ◽  
Oxygen Storage Capacity ◽  
Catalytic Performance ◽  
Oxygen Storage ◽  
Co2 Reforming ◽  
Co2 Reforming Of Methane ◽  
Effect Of Support

Enhanced catalytic performance of a Pt-xCeO2/Graphene catalyst for DMFCs by adjusting the crystal-plane and shape of nanoscale ceria

RSC Advances ◽  
2015 ◽  
Vol 5 (91) ◽  
pp. 74899-74906 ◽  
Author(s):  
Weihua Wang ◽  
Mingda Zhu ◽  
Xiaolin Lu ◽  
Yanfang Gao ◽  
Lijun Li ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Storage Capacity ◽  
Oxygen Storage Capacity ◽  
Catalytic Performance ◽  
Oxygen Storage ◽  
Crystal Plane

Oxygen storage capacity is influenced by the morphology and crystal-plane(s) of CeO2, which can thus affect the ability of this material to oxidise carbon monoxide.

scholarly journals High-throughput computational-experimental screening protocol for the discovery of bimetallic catalysts

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Byung Chul Yeo ◽  
Hyunji Nam ◽  
Hyobin Nam ◽  
Min-Cheol Kim ◽  
Hong Woo Lee ◽  
...  
Keyword(s):  
High Throughput ◽  
Bimetallic Catalysts ◽  
High Throughput Screening ◽  
Direct Synthesis ◽  
Catalytic Performance ◽  
Platinum Group Metals ◽  
Pt Catalyst ◽  
Electronic Density ◽  
Bimetallic Alloy ◽  
Screening Protocol

AbstractTo accelerate the discovery of materials through computations and experiments, a well-established protocol closely bridging these methods is required. We introduce a high-throughput screening protocol for the discovery of bimetallic catalysts that replace palladium (Pd), where the similarities in the electronic density of states patterns were employed as a screening descriptor. Using first-principles calculations, we screened 4350 bimetallic alloy structures and proposed eight candidates expected to have catalytic performance comparable to that of Pd. Our experiments demonstrate that four bimetallic catalysts indeed exhibit catalytic properties comparable to those of Pd. Moreover, we discover a bimetallic (Ni-Pt) catalyst that has not yet been reported for H2O2 direct synthesis. In particular, Ni61Pt39 outperforms the prototypical Pd catalyst for the chemical reaction and exhibits a 9.5-fold enhancement in cost-normalized productivity. This protocol provides an opportunity for the catalyst discovery for the replacement or reduction in the use of the platinum-group metals.

scholarly journals Nickel Phosphide Catalysts as Efficient Systems for CO2 Upgrading via Dry Reforming of Methane

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 446
Author(s):  
Miriam González-Castaño ◽  
Estelle le Saché ◽  
Cameron Berry ◽  
Laura Pastor-Pérez ◽  
Harvey Arellano-García ◽  
...  
Keyword(s):  
Supported Catalysts ◽  
Lower Surface ◽  
Catalytic Performance ◽  
Dry Reforming Of Methane ◽  
Oxidation Reactions ◽  
Surface Areas ◽  
Ceo2 Sample ◽  
Conversion Rates ◽  
Ni Oxidation ◽  
Catalytic Behaviour

This work establishes the primordial role played by the support’s nature when aimed at the constitution of Ni2P active phases for supported catalysts. Thus, carbon dioxide reforming of methane was studied over three novel Ni2P catalysts supported on Al2O3, CeO2 and SiO2-Al2O3 oxides. The catalytic performance, shown by the catalysts’ series, decreased according to the sequence: Ni2P/Al2O3 > Ni2P/CeO2 > Ni2P/SiO2-Al2O3. The depleted CO2 conversion rates discerned for the Ni2P/SiO2-Al2O3 sample were associated to the high sintering rates, large amounts of coke deposits and lower fractions of Ni2P constituted in the catalyst surface. The strong deactivation issues found for the Ni2P/CeO2 catalyst, which also exhibited small amounts of Ni2P species, were majorly associated to Ni oxidation issues. Along with lower surface areas, oxidation reactions might also affect the catalytic behaviour exhibited by the Ni2P/CeO2 sample. With the highest conversion rate and optimal stabilities, the excellent performance depicted by the Ni2P/Al2O3 catalyst was mostly related to the noticeable larger fractions of Ni2P species established.

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