Diesel Exhaust Research Articles

Predictive modeling and optimization of a waste cooking oil biodiesel/diesel powered CI engine: an RSM approach with central composite design

Due to the restrictions of the diesel engine emissions and the massive demand of energy, the fossil diesel fuel has been consumed quickly and the resources cannot suffice the demand. Alternative fuels that include bio alcohols, hydrogen and biodiesel can make up the diesel fuel depletion. Biodiesel is convenient for diesel engine operation due to its properties like fossil diesel properties. Response surface methodology is a statistical approach for responses prediction and optimization using definite number of experiments to provide time and cost. This study aims to predict and optimize the performance and emission attributes; of diesel engine has single cylinder and operates at 1400 rpm constant speed fuelled with pure diesel fuel or diesel fuel blended with waste cooked oil (WCO) biodiesel at different blending ratio by using response surface methodology (RSM). The influences of the independent variables that are WCO biodiesel blend percentages and the diesel engine load values on the responses that are predicted and optimized. The WCO biodiesel/ diesel fuel blend percentages are pure diesel fuel without biodiesel (B0), 40% WCO biodiesel with 60% diesel fuel (B40) and 80% WCO biodiesel with 20% diesel fuel (B80). The experiments are performed using diesel engine runs at 1400 rpm constant speed, at varying diesel engine loads are zero, 4 and 8 kW. The design of experiments (DOE) is attempted using central composite design (CCD). The RSM model is a nonlinear model developed according to the independent variables and the responses. The homogeneity between the independent variables is studied to predict and optimize their influences on the diesel engine performance and emission attributes. The RSM model is validated according to the coefficients of regression are R2, R2 adjusted and the R2 predicted that prove the satisfaction of the results. From the experiments it is observed that diesel engine performance and emissions attributes are enhanced by increasing the diesel engine load value and increasing the percentage of WCO biodiesel blending ratio compared to pure diesel only like NOx emissions which reduced from 1200 ppm to 900 ppm at the same engine load due to the reduced combustion temperatures using WCO biodiesel. According to the response optimizer tool, the optimal responses are 17.11% for the BTE, 658.9 ppm for the NOx emissions and 1.93% for CO2 emission at independent variables are 2.6667 kW diesel engine load and 100% pure diesel fuel.

Experimental Study of the Effect of Plastic Pyrolysis Oil on the Physical-Chemical Properties of Rubber Seed Biodiesel and Diesel Engine Performance using a Mixture of Plastic Pyrolysis Oil-Rubber Seed Biodiesel-Diesel Fuel

Rubber seed oil is a potential source of biodiesel, but its utilization is still limited. From previous research studies, the addition of Rubber Seed Biodiesel (RSB) to diesel will reduce engine performance and increase BSFC but can increase emissions. At the same time, plastic waste has posed a very serious environmental challenge due to its large quantity and suboptimal processing problems. Pyrolysis is considered to be an efficient solution for handling plastic waste, because it operates at low pressure and produces Plastic Pyrolysis Oil (PPO) as fuel. The success of research on converting plastic waste into fuel can be a solution to limited biodiesel raw materials, as well as a solution for handling plastic waste. From various previous studies it is known that PPO has a higher heating value than biodiesel, but biodiesel has a higher centane number. Based on these various symptoms, it is interesting to research the use of a mixture of RSB and PPO fuels, because they are thought to complement each other. In this research, PPO was added to RSB starting at 10%, 20%, 30% and 40%, then the physicochemical properties of each mixture were examined, it was found that PPO could increase the heating value, reduce viscosity, density and acid number, reduce the cetane number and reduces the oxidation stability of RSB. To test on a diesel engine, PPO was added to the diesel-RSB mixture. The diesel portion is set at 60%, while the RSB and PPO portions are varied starting from 40% RSB 0% PPO, 30% RSB 10% PPO, 20% RSB 20% PPO and 10% RSB 30% PPO. Diesel engine performance and emissions were investigated when PPO was added to the fuel mixture. The search results show that BTE decreased by 4% when using B10P30 compared to using pure diesel, but increased by around 30% compared to using RSB40 at full load. The addition of PPO to the Diesel-RSB mixture increases CO, HC and smoke emissions, but is still lower than pure diesel emissions.

A sustainable Response Surface Methodology and Analytic Hierarchy Process - Weighted Aggregated Sum Product Assessment model to Evaluate Performance and Emissions Characteristics of Diesel engine using Clove Oil Biodiesel Blend

Abstract Replacing diesel with biodiesel generally results in a decrease in exhaust emissions like carbon monoxide, hydrocarbon, particulate matter, and carbon dioxide. However, nitrogen oxide emissions show increasing trends. On the other hand, a decrease in nitrogen oxide emissions has been found using various additives with diesel and biodiesel blends. In this work the experimentations are carried out on diesel, B30 (70% v/v diesel+30% v/v biodiesel), and the B30CL1000 (70% v/v diesel+30% v/v biodiesel+1000 ppm clove oil) to evaluate the performance and emissions of diesel engine. The Response Surface Methodology based approach has been applied to evaluate the effect of different engine operating parameters on engine performance and emission while fueled with the B30CL1000 fuel blend. Further, the Analytic Hierarchy Process - Weighted Aggregated Sum Product Assessment method has been applied to identify the optimal setting of the parameters and rank the optimal engine operating range for the B30CL1000 blend. From results, elicited that the accumulation of 1000 ppm of antioxidant (clove oil) additives in the B30 blend resulted in a reduction in the brake-specific fuel consumption by up to 11.5% at higher loads. Brake thermal efficiency increased by 16.3% at low load conditions for the B30CL1000 blend. After that the B30CL1000 blend showed a 2% drop in carbon monoxide emission at higher loads and the decreased nitrogen oxide emission for the B30CL1000 blend has been also reported as 12% at low loads and 2% at higher loads which follows a similar trend as exhaust gas temperature. The 5th experimental run having CR (17), EGR (0%) and Load (12kg) has been ranked as 1.

Analysing Battery Swapping of Battery Electric Load Haul Dump (LHD) Machines in Block Cave Mining Using Discrete Event Simulation (DES)

AbstractDiesel-powered load haul dump machines have been the backbone of underground mining loading and hauling operations for over six decades. However, as mines get deeper, and regulations become more rigorous, the adoption of battery electric vehicles (BEVs) has the potential to enhance energy efficiency and provide a healthier environment for miners. Electric engines have a significantly higher energy efficiency and produce no exhaust gases or diesel particulate matter. The use of BEVs in underground operations introduces additional factors to consider, such as battery swapping and the required number of batteries, swapping, and charging stations. This study conducted a discrete event simulation using Arena simulation software with a focus on queueing and its relationship to different numbers of machines, batteries, and swapping times in an underground block cave mine. The results suggest that when there are six, eight, or 12 LHDs and four swapping and charging stations with an unlimited number of batteries, the queueing time to swap the batteries remains minimal. In scenarios with eight LHDs and a limited number of batteries, depending on the battery swapping time, 2–2.5 batteries per machine are required to achieve maximum production with minimal queueing. However, when there are too few batteries, queueing becomes significant. Moreover, when the number of working groups (machines going for a battery swap around the same time) is less than the ratio between the battery operational time and the swapping time, the queueing remains low.

Validation of Magnesium Oxide Additive Effects on Diesel Engine Performance Through Crystal Structure and Thermal Stability Analyses

ABSTRACTThis study investigates the effects of magnesium oxide (MgO) nanoparticles on combustion performance and emissions in diesel engines. MgO's well‐ordered crystal structure, high thermal stability, and oxygen‐carrying capacity positively influence engine performance. The effects of 50 and 100 mg/L MgO concentrations were compared, showing up to a 5% improvement in brake thermal efficiency at 100 mg/L. Additionally, reductions of 8% in CO and 10% in HC emissions were achieved. MgO's crystal structure contributed to higher combustion temperatures, leading to lower harmful emissions. However, an increase in NOx emissions was observed, indicating the need for careful balancing between performance improvements and emission control. These results highlight MgO as an efficient and environmentally friendly fuel additive.

Co-Ce Clay-Based Materials: Their Feasibility as Catalysts for Soot and CO Oxidation Reactions

A series of Co-Ce clay-based catalysts were prepared via the wet impregnation method and tested for the catalytic combustion of diesel soot and carbon monoxide. The objective of this work was to find a suitable catalyst with an optimized active phase composition in order to structure this system using a 3D-printing technique. The physicochemical characterization indicated that the support was mainly composed of kaolinite and quartz. When supported on commercial clay, the mixture of oxides (Co3O4 spinel and CeO2 fluorite) had higher activity than the individual oxides. The formation of a solid Co-Ce solution was verified along with a synergistic effect between these two selected metal oxides. The optimal molar composition was Co:Ce = 90:10. The corresponding catalyst showed the highest catalytic activity for soot combustion, with 335 °C being the temperature of the maximum combustion rate. Also, it produced the best system for CO oxidation. This formulation showed a balanced proportion of Co3+ and Co2+ on the surface and had the highest content of Ce3+ surface species among the catalysts prepared, which played a key role in the oxidation reactions studied.

Impact of Short-Term Diesel Exhaust Exposure on Prothrombotic Markers in Chronic Obstructive Pulmonary Disease: A Randomized, Double-Blind, Crossover Study.

Rationale: Growing evidence suggests that air pollution exposure is a major risk factor in chronic obstructive pulmonary disease (COPD) that is associated with an increased prothrombotic state and adverse cardiovascular outcomes. However, much of this work is based on observational data or human exposure studies involving younger participants. The biological causality and mechanism of air pollution-induced prothrombotic response in patients with COPD remain to be explored. Objectives: The main aim of this work was to investigate the impact of short-term diesel exhaust (DE) exposure on circulating prothrombotic markers-fibrinogen and plasminogen activator inhibitor-1 (PAI-1)-and urinary eicosanoids in patients with COPD. Methods: Twenty-nine research participants were recruited in this randomized, double-blind, crossover, controlled human exposure study to DE. Participants included former smokers with and without mild or moderate COPD (ex-smokers [ES] and COPD group) and healthy never-smokers without COPD (nonsmoker [NS] group). Each participant was exposed to DE (300 μg/m3 of particulate matter with an aerodynamic diameter ≤2.5 μm) and filtered air for 2 hours on different occasions, in randomized order, separated by a 4-week washout. Blood and urine samples were collected before and 24 hours after each exposure. Plasma fibrinogen and serum PAI-1 concentrations were quantified using enzyme-linked immunosorbent assays. Urinary eicosanoid concentrations were quantified using ultraperformance liquid chromatography coupled to tandem mass spectrometry. Linear mixed-effects models were used for statistical comparisons. Results: Participants with COPD showed an increase in plasma fibrinogen (effect estimate, 1.27 [1.06-1.53]; P = 0.01) after DE relative to filtered air, but no significant DE-associated change in serum PAI-1 (0.95 [0.87-1.04]; P = 0.26). In never-smokers and ex-smokers without COPD, fibrinogen (NS group, 1.10 [0.99-1.23]; P = 0.08; ES group, 0.86 [0.68-1.09]; P = 0.08] and PAI-1 (NS group, 1.12 [0.96-1.32]; P = 0.15; ES group, 0.90 [0.79-1.03]; P = 0.13) were not changed after DE exposure. Participants with COPD showed a DE-attributable increase in urinary thromboxane B2 (TXB2) metabolite concentrations as follows: 11-dehydro-TXB2 (1.45 [1.02-2.08]; P = 0.04) and 2,3-dinor-TXB2 (1.45 [1.05-2.00]; P = 0.03). Conclusions: Participants with COPD had increased plasma fibrinogen and urinary TXB2 metabolites after short-term DE exposure, suggesting they may be more susceptible to a pollution-attributable prothrombotic response than healthy control subjects or ex-smokers without COPD. Clinical trial registered with www.clinicaltrials.gov (NCT02236039).

Impact of hydrogen induction on atomization combustion performance and emissions in diesel engines fueled with heated biodiesel blends

Impact of hydrogen induction on atomization combustion performance and emissions in diesel engines fueled with heated biodiesel blends

Microwave activation of Cu/SSZ-13 zeolite for widening active temperature window of NO from diesel exhaust

Microwave activation of Cu/SSZ-13 zeolite for widening active temperature window of NO from diesel exhaust

Engineering the structure defects of ceria-zirconia-praseodymia solid solutions for diesel soot catalytic elimination

Creating structure defects in ceria-based solid solution catalysts is a crucial yet challenging task. Herein, urea-assisted synthesis strategy was designed for ceria-zirconia-praseodymia catalyst (CeZrPrOx) to create lattice defects; its effects on catalyst structure, physical-chemical properties and catalytic diesel soot purification activity were systematically investigated. Raman and X-ray photoelectron spectroscopy (XPS) findings indicate that the urea-assisted synthesized catalyst (CeZrPrOx-U) has remarkably more Ce3+ proportion (structure defects), oxygen vacancies and surface reactive oxygen species (O22- and O2-). Temperature-programmed reduction by hydrogen (H2-TPR) and temperature-programmed desorption by oxygen (O2-TPD) results further prove that the oxygen migration of the CeZrPrOx-U is definitely enhanced. Compared to the conventional CeZrPrOx catalyst, the bulk lattice oxygen of the CeZrPrOx-U can be migrated to the surface to generate surface reactive oxygen species more easily. As a consequence, the prepared CeZrPrOx-U catalyst exhibits obviously better catalytic diesel soot purification activity. Therefore, this study suggests that engineering the structure defects in CeZrPrOx catalyst is an effective approach to improve physical-chemical properties and enhance the soot catalytic elimination activity of the catalyst.

Protective Potentials of Extracted Compound Silibinin from Milk Thistle on Type-2 Diabetes Mellitus and Diesel Exhaust Particle (DEP) Toxicity in Experimental Rats

Protective Potentials of Extracted Compound Silibinin from Milk Thistle on Type-2 Diabetes Mellitus and Diesel Exhaust Particle (DEP) Toxicity in Experimental Rats

Exploring Eco-Friendly Paths: A Comparative Study of Emissions in Medium Speed Diesel Engines Utilizing Alternative Fuels through Simulation Analysis

In the ship industry, emissions from marine activities have been shown to influence air quality and climate, with pollutants such as sulphur dioxide (SO2), nitrogen oxides (NOₓ), and Carbon Dioxide (CO2). the International Maritime Organization (IMO) has implemented MARPOL Annex VI to reduce emissions from maritime activities, one of which is using alternative fuels. With the need of sustainable energy source of reducing emissions, the evaluation of alternative fuels becomes crucial. This study presents a comparative analysis of performance and environmental emissions from medium speed diesel engines utilizing different fuels, namely Biodiesel (B10-100), Heavy Fuel Oil (HFO), and Ultra Low Sulphur Fuel Oil (ULSFO) under various engine speed. the research was carried out using the Diesel-RK application with Internal Combustion Engine simulation that integrates thermodynamics and emission prediction algorithms to accurately represent the combustion process and subsequent pollutant formation. Parameters such as engine load, injection timing, and fuel properties are systematically varied to assess their impact on emissions of nitrogen oxides (NOₓ), sulfur dioxides (SO2), and carbon dioxide (CO2). Results indicate distinct performance and emission profiles for each fuel type in various engine speed. All Biodiesel and ULSFO demonstrates increasing NOₓ emissions compared to HFO with an average of 51.4%. However, they exhibit lower CO2 and SO2 compared to HFO with average of 3% for CO2 and 98.8% for SO2, this is due to higher oxygen content that can promote more efficient combustion, and both Biodiesel and ULSFO contains lower sulphur content.

Ferroptosis in the Substantia Nigra Pars Compacta of Mice: Triggering Role of Ultrafine Diesel Exhaust Particles and Mitigation by α-Lipoic Acid.

Recent epidemiological and experimental studies have increasingly highlighted the association between environmental pollution, especially ultrafine particulate matter (PM), and the risk of neurodegenerative diseases, such as Parkinson's disease (PD). These previous studies suggest a potential mechanism by which ultrafine PM contributes to neuronal damage through processes, such as iron accumulation and oxidative stress. In this study, we aimed to elucidate the effects of ultrafine PM on ferroptosis, an iron-dependent form of cell death, in the mouse substantia nigra pars compacta (SNc) and to evaluate the protective role of α-lipoic acid (ALA). Mice were exposed to ultrafine diesel exhaust particles (ufDEP), a type of ultrafine PM, intranasally and injected ALA intraperitoneally for seven consecutive days. Iron accumulation and lipid peroxidation were significantly increased, and antioxidant capacity was significantly decreased in the SNc after ufDEP exposure, highlighting the deleterious effects of ufDEP on tyrosine hydroxylase (TH)-positive neurons. In contrast, ALA treatment effectively mitigated these effects by reducing iron accumulation, decreasing lipid peroxidation, and restoring antioxidant levels, resulting in the protection of TH-positive neurons from ferroptotic damage. Our results provide evidence that ufDEP can induce ferroptosis in dopaminergic neurons in the SNc, potentially contributing to PD pathogenesis. Furthermore, ALA showed protective effects against ufDEP-induced ferroptotic damage, suggesting its potential as a therapeutic intervention for PD.

Transcriptomic and epigenomic profiling reveals altered responses to diesel emissions in Alzheimer's disease both in vitro and in population-based data.

Studies have correlated living close to major roads with Alzheimer's disease (AD) risk. However, the mechanisms responsible for this link remain unclear. We exposed olfactory mucosa (OM) cells of healthy individuals and AD patients to diesel emissions (DE). Cytotoxicity of exposure was assessed, mRNA, miRNA expression, and DNA methylation analyses were performed. The discovered altered pathways were validated using data from the human population-based Rotterdam Study. DE exposure resulted in an almost four-fold higher response in AD OM cells, indicating increased susceptibility to DE effects. Methylation analysis detected different DNA methylation patterns, revealing new exposure targets. Findings were validated by analyzing data from the Rotterdam Study cohort and demonstrated a key role of nuclear factor erythroid 2-related factor 2 signaling in responses to air pollutants. This study identifies air pollution exposure biomarkers and pinpoints key pathways activated by exposure. The data suggest that AD individuals may face heightened risks due to impaired cellular defenses. Healthy and AD olfactory cells respond differently to DE exposure. AD cells are highly susceptible to DE exposure. The NRF2 oxidative stress response is highly activated upon air pollution exposure. DE-exposed AD cells activate the unfolded protein response pathway. Key findings are also confirmed in a population-based study.

Effects of particulate air pollution on BPDE-DNA adducts, telomere length, and mitochondrial DNA copy number in human exhaled breath condensate and BEAS-2B cells

Traffic-related particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) have been linked to respiratory diseases and cancer risk in humans. Genomic damage, including benzo[a]pyrene diolepoxide (BPDE)-DNA adducts as well as alterations in telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN) are associated with respiratory diseases. This study aimed to investigate the association between exposure to traffic-related particulate pollutants and genomic damage in exhaled breath condensate (EBC) in human subjects and a bronchial epithelial cell line (BEAS-2B). Among the 60 healthy recruited subjects, residents living in high-traffic-congested areas were exposed to higher concentrations of PM2.5 (1.66-fold, p < 0.01), UFPs (1.79-fold, p < 0.01), PM2.5-PAHs (1.50-fold, p < 0.01), and UFPs-PAHs (1.35-fold, p < 0.05), than those in low-traffic-congested areas. In line with increased exposure to particulate air pollution, the high-traffic-exposed group had significantly increased BPDE-DNA adducts (1.40-fold, p < 0.05), TL shortening (1.24-fold, p < 0.05), and lower mtDNA-CN (1.38-fold, p < 0.05) in EBC. The observations in the human study linking exposure to PM2.5, UFPs, PM2.5-PAHs, and UFPs-PAHs with the aforementioned biological effects were confirmed by an in vitro cell-based study, in which BEAS-2B cells were treated with diesel exhaust particulate matter (DEP) containing fine and ultrafine PM and PAHs. Increased BPDE-DNA adducts levels, shortened TL, and decreased mtDNA-CN were also found in treated BEAS-2B cells. The shortened TL and decreased mtDNA-CN were in part mediated by decreased transcript levels of hTERT, and SIRT1, which are involved in telomerase activity and mitochondrial biogenesis, respectively. These results suggest that exposure to traffic-related particulate pollutants can cause genomic instability in respiratory cells, which may increase the health risk of respiratory diseases and the development of cancer.

Source apportionment of ultrafine particles in urban Europe

There is a body of evidence that ultrafine particles (UFP, those with diameters ≤ 100 nm) might have significant impacts on health. Accordingly, identifying sources of UFP is essential to develop abatement policies. This study focuses on urban Europe, and aims at identifying sources and quantifying their contributions to particle number size distribution (PNSD) using receptor modelling (Positive Matrix Factorization, PMF), and evaluating long-term trends of these source contributions using the non-parametric Theil-Sen’s method. Datasets evaluated include 14 urban background (UB), 5 traffic (TR), 4 suburban background (SUB), and 1 regional background (RB) sites, covering 18 European and 1 USA cities, over the period, when available, from 2009 to 2019. Ten factors were identified (4 road traffic factors, photonucleation, urban background, domestic heating, 2 regional factors and long-distance transport), with road traffic being the primary contributor at all UB and TR sites (56–95 %), and photonucleation being also significant in many cities. The trends analyses showed a notable decrease in traffic-related UFP ambient concentrations, with statistically significant decreasing trends for the total traffic-related factors of −5.40 and −2.15 % yr−1 for the TR and UB sites, respectively. This abatement is most probably due to the implementation of European emissions standards, particularly after the introduction of diesel particle filters (DPFs) in 2011. However, DPFs do not retain nucleated particles generated during the dilution of diesel exhaust semi-volatile organic compounds (SVOCs). Trends in photonucleation were more diverse, influenced by a reduction in the condensation sink potential facilitating new particle formation (NPF) or by a decrease in the emissions of UFP precursors. The decrease of primary PM emissions and precursors of UFP also contributed to the reduction of urban and regional background sources.

Particle emission and thermal efficiency analysis of a diesel vehicle using biodiesel and a platinum metallic partial-flow particulate filter

Harmful emissions from diesel vehicles, particularly unmodified ones, pose significant concerns for human health and the environment, underscoring the urgency to address these issues. This study investigated the effects of commercial fuels, B10, B20, and biodiesel B100, used with a metallic partial-flow catalyzed diesel particulate filter (P-CDPF), on a light-duty unmodified diesel vehicle's thermal efficiency and emissions characteristics. The initial test was conducted on a chassis dynamometer to measure the fuel flow rates at three different engine speeds, 1500, 2000, and 2500 rpm, with four loads, 84, 112, 140, and 160 Nm. This was done to evaluate brake-specific fuel consumption and brake thermal efficiency under steady-state conditions. The second test followed the new European driving cycle to examine emission factors of regulated pollutants under both urban and highway driving conditions. The results indicated that BSFC values increased with the biodiesel ratio in the blends, attributed to lower heating values. However, higher oxygen contents with increasing biodiesel ratios led to more complete combustion and improved brake thermal efficiency. Installation of a P-CDPF had a minimal impact, resulting in less than a 3.4% increase in the BSFC and a 1% decrease in brake thermal efficiency across all tested fuels, owing to its relatively low pressure drop. Increasing the biodiesel ratio from B10 and B20 to B100 resulted in reductions of up to 32% of particulate mass and 45% of particulate number in vehicle emissions. P-CDPF installation further reduced particulate mass by over 60% and particulate number by 36% across all tested fuels, demonstrating its effectiveness in trapping and passively oxidizing particulate matter. Furthermore, the P-CDPF significantly reduced harmful gases with addition of a catalytic coating. A combination of a P-CDPF and commercial biodiesel fuels emerges as an effective solution for reducing regulated emissions from unmodified diesel vehicles.

Mitochondrial Toxicity of PM2.5 Leads to Cardiac Failure: A Comparative Evaluation of PM2.5 from Ambient Air, Diesel Exhaust and SRM 2975

Mitochondrial Toxicity of PM2.5 Leads to Cardiac Failure: A Comparative Evaluation of PM2.5 from Ambient Air, Diesel Exhaust and SRM 2975

Palladium-assisted NOx storage and release on CexZr1-xO2 for passive NOx adsorber in diesel exhaust aftertreatment

Understanding Pd effects on NOx storage and release is crucial for designing passive NOx adsorber (PNA) to control NOx emissions during diesel cold-starts. Herein, we report two oxidation states of Pd species on CexZr1-xO2 regulated by metal-support interaction. Pdδ+ (0 < δ < 2) in Pd/Ce0.25Zr0.75O2 exhibits a high affinity for O2 adsorption, which promotes the oxidation of adsorbed NO to nitrates at 100 °C. These nitrates are thermally unstable due to electron transfer from the Pd atom to the N-O bond, facilitating the decomposition of nitrates to NO2 above 200 °C. In contrast, Pd2+ in Pd/Ce0.75Zr0.25O2 prefer to NO adsorption. A large amount of adsorbed NO and nitrites accumulate on Pd2+ and Ce4+ results in high levels of NO release below 200 °C. For the potential application in PNA, Pd/Ce0.25Zr0.75O2 is recommended due to its proper NOx release temperature as well as better water and SO2 resistance.

Optimization of Biodiesel–Nanoparticle Blends for Enhanced Diesel Engine Performance and Emission Reduction

Optimization of Biodiesel–Nanoparticle Blends for Enhanced Diesel Engine Performance and Emission Reduction