Chlorine Poisoning Research Articles

Plasma driven exsolution of Ca as the adjacent dechlorinated site in La0.8Ca0.2MnO3 perovskite: A highly mineralization chlorobenzene oxidation catalyst

The degradation of chlorine-containing volatile organic compounds (CVOCs) catalytic combustion technology is subject to the catalyst chlorine poisoning, which is resulted from the chlorination of active phases, even though the structural stable perovskite. The reaction between Ca species and dissociated chlorine species is demonstrated as an efficient way to inhibited chlorine poisoning of the active phase. Herein, a Ca substituted partial La prepared La0.8Ca0.2MnO3 (named as L8C2MO) perovskite was treated by 5% H2/Ar plasma driven route (the treated sample was denoted as L8C2MO-P), which was applied for the chlorobenzene oxidation removal. The integrated characterization results of XRD, XPS, HRTEM, etc. confirmed that Ca (mainly exhibited as CaCO3) was successfully exsolved from La0.8Ca0.2MnO3 and simultaneously leaved oxygen vacancies on the surficial layers. The continuous catalytic oxidation experiments illustrated that the conversion efficiency of L8C2MO was unexpectedly decreased compared with that of LaMnO3 (LMO in short) sample, while that of L8C2MO-P was nearly maintained the oxidation capacity, with approximately 12 °C of 90% chlorobenzene conversion temperature (T90) higher than that of LMO. Importantly, the CO2 and inorganic chlorine species yields were significantly enhanced for L8C2MO and L8C2MO-P. The characteristic of used samples showed a possible chlorinated Ca species formation while the status of Mn phases was hardly changed, suggesting the exsolved Ca could inhibit the poison of Mn sites by binding with dissociative chlorine species. Additionally, oxygen vacancies that generated along with Ca exsolution process was definitely contributed to the deep oxidation of chlorobenzene. The possible reaction route was also studied by in situ DRIFTS and GCMS. The work provides a potential route as in situ growth of adjacent sites to protect active phases from chlorine poison in CVOCs catalytic oxidation process.

Catalytic oxidation of dichloromethane over W-Nb composite oxide catalysts modified by Co: The influence of redox ability and acidity

Catalytic oxidation of highly toxic chlorinated volatile organic compounds often places high demands on the anti-poisoning ability of the catalysts. Here, Co/WNb catalysts with different Co loadings were prepared for the catalytic oxidation of dichloromethane (DCM). Notably, the interaction between the active components and the carriers resulted in a high Co2+/Co3+ ratio on the catalyst surface, which facilitated the generation of oxygen vacancies (Ov) and enhanced the redox properties of the catalyst. Furthermore, the WNb carrier offered ample surface acidic sites, bolstering the catalyst's resilience against chlorine poisoning. The study revealed that achieving a more balanced combination of redox properties and acidity was beneficial for enhancing the catalytic degradation efficiency of DCM. 3% Co/WNb exhibited the best catalytic activity (T90 = 269 °C). The catalyst also exhibited excellent stability and outstanding water resistance. Potential reaction routes for the catalytic oxidation of DCM were explored using in-situ IR spectra analysis. This study offers novel insights for the development of efficient, stable, and environmentally friendly catalysts for DCM degradation.

Enhanced Ru-O-Ce interaction by solid solution structure of Ru-CexZr1-xO2 catalysts for efficient catalytic combustion of vinyl chloride

Ru-CexZr1-xO2 catalysts, prepared by stepwise precipitation method, were investigated for the catalytic combustion of vinyl chloride (VC). Ru-O-Ce is a highly reactive structure in the redox ability. The Ce-O-Zr solid solution structure enhances the strong metal-support-interaction (SMSI) between Ru and Ce, thereby increasing the content of Ru-O-Ce structure, which can be modulated by the molar ratio of Ce/(Ce + Zr) in the catalyst. Zr doping also enhances the surface acid sites. In situ DRIFTS reveals that Ru-CexZr1-xO2 catalyst avoids chlorine poisoning, and Ru-O-Ce provides sufficient chemically adsorbed oxygen species (CAOS) to promote formation of formate intermediate species. Ru-Ce0.5Zr0.5O2 catalyst exhibited the best catalytic performance with T90 of 227 °C under the reaction conditions of 1000 ppm VC and WHSV of 30,000 mL·g−1·h−1. Moreover, Ru-Ce0.5Zr0.5O2 catalyst exhibited the superior resistance to high temperature, chlorine poisoning and water, and excellent catalytic activity for the catalytic combustion of various VOCs.

Pulmonary Manifestations of Chlorine Gas Poisoning.

Pulmonary Manifestations of Chlorine Gas Poisoning.

Effect of acid sites modification on the catalytic combustion of 1,2-dichloroethane: Revealing the synergy between NbOx and CeO2

1,2-Dichloroethane are primarily sourced from the emissions of the chlor-alkali industry, resulting in severe pollution of soil, air, and water. In this work, Nb/CeO2 catalysts were prepared by impregnation method, and their performance for EDC oxidation was evaluated. The addition of Nb improved the activity, selectivity, and stability of CeO2. Nb was highly dispersed on CeO2 surface in the form of NbOx, and partially entered the lattice of CeO2. This caused lattice distortion and more surface defects, thereby increasing the number of oxygen vacancies. NbOCe bonds formed in between Nb and CeO2 weakened the CeO bonds and enhanced lattice oxygen mobility. The presence of NbOx increased the number of Lewis acid (NbO) and Brønsted acid (Nb-OH) sites, which facilitated the cleavage of CCl and CC bonds. Increased acidity promoted the removal of Cl species in the form of HCl and effectively mitigated the chlorine poisoning of CeO2. In-situ DRIFTS results indicated that EDC oxidation on Nb/CeO2 catalysts followed a Mars-van Krevelen mechanism and progressed via the pathway of alcoholate → formate/methoxy → COx.

Chlorine Gas Poisoning in an Aquatic Exercise Pool: A Case Report

Background and Purpose: This case report describes an incident of chlorine gas poisoning in an aquatic exercise class of senior adults in which 24 participants, facility employees, and first responders required emergency medical attention with some requiring hospitalization. The cause of the chlorine gas release, the health effects on participants, and the facility's subsequent response are described. The purpose of this case is to inform physical therapists and exercise professionals working in aquatic exercise pools about chlorine gas poisoning prevention and mitigation efforts. Case Description: The cause of this incident was a series of breakdowns in safety procedures leading to the release of chlorine gas while a class was in session. Because of limited exit points, physical debilitation of some participants, and a lack of proper safety equipment, the evacuation effort was delayed, overwhelming participants, facility employees, and first responders with toxic gas. Twenty-four people were transported to the emergency department with 7 hospitalized. At least 3 are known to suffer long-term health effects. Outcomes: The facility concluded that normal operating procedures and safety protocols were not followed. Following the review, the facility took measures to ensure adherence to proper procedures, revised its emergency action plan, and acquired the appropriate safety equipment. Discussion: The accidental release of chlorine gas in an exercise pool is a rare but potentially catastrophic event. Facilities operating exercise and aquatic therapy pools must follow strict protocols for the safe handling of pool chemicals and be prepared to respond immediately if a chlorine gas accident occurs. This case report serves as an example of risk management for the prevention of and response to a catastrophic release of chlorine gas during a group exercise or aquatic therapy session.

Low-temperature catalytic performance improvement of Ru/TiO2{001} for o-dichlorobenzene oxidation

Chlorinated aromatics hydrocarbons were harmful to ecology and human health, whose catalytic combustion encounters problem of catalyst deactivation by chlorine poisoning. To simultaneously improve the catalytic activity, CO2 selectivity and stability of catalyst, the present study used the loading of Ru active component on the anatase TiO2 which preferentially exposes highly active {001} crystalline facets. Take o-dichlorobenzene (o-DCB) oxidation as a surrogate reaction, Ru/TiO2{001} showed lower T90% (temperatures with 90% conversion), higher CO2 selectivity and better stability than Pt/TiO2{001}, Pd/TiO2{001} and Ru/commercial TiO2 (Ru/TiO2-C). The excellent results could be attributed to the strong metal support interaction between Ru species and TiO2{001}, with more oxygen vacancies and higher surface oxygen concentration, more Lewis acid sites, enhanced low-temperature reducibility, more surface Ti3+ species, more surface Ru4+ species, and highly dispersed Ru species, favoring the excellent low temperature catalytic activity and CO2 selectivity of Ru/TiO2{001}. In addition, the less Cl species on the used 1.5% Ru/TiO2{001} indicated their effectively removal, which is the core issue for the deep oxidation of o-DCB. Furthermore, the in situ FTIR spectroscopy gave the detail oxidation route of o-DCB over 1.5% Ru/TiO2{001}, that the co-adsorption of o-DCB and O2 on Ru/TiO2{001} surface were calculated based on the density functional theory calculations. The present study gave a new insight into the new pathway for the design of promising catalysts for the treatment of CAHs.

Tandem supported Pt and ZSM-5 catalyst with separated catalytic functions for promoting multicomponent VOCs oxidation

The painting and electronics industries simultaneously release aromatic compounds and chlorinated organics. The development of catalysts with synergistic control of these pollutants is of great significance to achieve air purification. However, developing active catalysts while maintaining good chlorine resistance remain a huge challenge due to the difficulty of the trade-off between the redox properties and acidity and the production of polychlorinated byproducts. Herein, we introduce a novel tandem PtSn/CeO2&Mn/ZSM-5 catalyst and investigate its catalytic performance for multicomponent volatile organic compounds (VOCs) oxidation. The two individual catalysts, PtSn/CeO2 and Mn/ZSM-5, were used to catalyze two distinct sequential reactions. PtSn/CeO2 catalyzed toluene oxidation to produce CO2 and H2O. Meanwhile, the introduction of SnOx favored the adsorption of trichloroethylene (TCE) molecules that prevented Pt sites from chlorine poisoning and possibly converted adsorbed TCE into intermediates, which were subsequently oxidized deeply by the nearby Mn/ZSM-5. This approach resulted in a remarkable oxidation efficiency for toluene (T90 = 296 °C) and TCE (T90 = 384 °C), with fewer unexpected toxic byproducts (chlorobenzene and 4-chlorotoluene). Furthermore, the tandem catalyst possessed excellent chlorine and water resistances. In conclusion, the above findings provide new insights into the design and/or syntheses of advanced catalysts for widespread VOCs pollution control.

Simultaneous catalytic removal of NO and chlorobenzene over MnCeSmSnOx: Catalytic performance and removal mechanism

Mn-based catalysts have great potential in the synergistic removal of NO and chlorobenzene but exhibit serious chlorine poisoning and low catalytic activity at low temperatures. In this study, the performance of MnCeOx for simultaneous catalytic removal of NO and chlorobenzene at low temperatures was optimized by the modification of Sm and Sn. Results showed that the modification of Sm and Sn afforded a loose overall structure of the catalyst with a large specific surface area. The addition of Sm and Sn effectively increased the concentration of Mn4+, Ce3+, chemisorbed oxygen, and the amount of acid on the catalyst surface. This considerably improved the activity of the catalyst for simultaneous removal of NO and chlorobenzene at low temperatures. The intermediates formed by the MCSS-0.086 catalyst during the low-temperature simultaneous catalytic removal of NO and chlorobenzene were CHCl3, CCl4, C2HCl3, and C2Cl4. The presence of SnO2 promoted the deep oxidation of chlorobenzene and inhibited the chlorine poisoning of the catalyst. Thus, the low-temperature stability of the catalyst was improved. The chlorobenzene-oxidation efficiency and the NO-removal efficiency of MCSS-0.086 were more than 90% and 95%, respectively, within the range of 178 °C-300 °C. The NH3-selective catalytic reduction curve of NO removal over the MnCeSmSnOx catalyst followed the Langmuir–Hinshelwood mechanism at low temperatures. The catalytic degradation of chlorobenzene finally yielded small molecules: CO2, H2O, and HCl.

Reactive airway dysfunction syndrome caused by chlorine gas from the point of view of Persian Medicine: A review article

Introduction: Chlorine gas inhalation is a toxic respiratory irritant associated with high lung complications. Despite its wide industrial and domestic applications such as bleaching detergents, there is no specific treatment for chlorine gas poisoning yet and common standard treatments are mostly supportive. In this regard, this study aimed to find a new treatment for this pathogenesis from the perspective of Persian medicine (PM).
 Materials and methods: In this review study, at first, we searched the etiologies and clinical symptoms associated with chlorine gas poisoning in modern medicine and then compared them with similar etiologies and symptoms in valuable Persian medical manuscripts. Then we reviewed the proposed treatments for similar illnesses from the point of view of PM.
 Results: The pathology of lung damage caused by inhalation of chlorine gas is reactive airway dysfunction syndrome (RADS), which leads to dyspnea, hypoxemia, respiratory tract obstruction, pneumonia, pulmonary edema, and finally acute respiratory distress syndrome (ARDS). In a comparative study, it seems that this pathology has the closest similarity with the Persian term“Varme-e-harr riye”. The treatment strategy for this syndrome in PM is bloodletting at the first and then the application of cold-temperament foods and medications to improve the lungs.
 Conclusion: According to the compatibility of acute pulmonary edema caused by chlorine inhalation and “varam-e-harr riye” in PM, it seems that wet cupping can be considered as a suggested primary and emergency treatment for this pathology in future clinical studies.

Enhanced catalytic elimination of chlorobenzene over Ru/TiO2 modified with SnO2—Synergistic performance of oxidation and acidity

The chlorine poisoning of catalyst caused by catalytic oxidation of CVOCs after long-term operation is still the bottleneck of its large-scale industrial application. In this work, Ru-xSn/TiO2 catalysts with oxidation and acid function were prepared by the typical impregnation method, and the catalytic oxidation of chlorobenzene (CB) was also investigated. Meanwhile, the doping of Sn could make the catalyst maintain excellent activity on the basis of reducing the content of noble metals. The optimal catalytic oxidation activity of CB was obtained by doping 10 % Sn on 0.4Ru/TiO2, and the T10 and T90 values were 140 °C and 195 °C, respectively, which were similar to that of 2.0Ru/TiO2. SnO2 improved the concentration of Ru4+ on the surface of the catalyst and formed a solid solution with TiO2 to promote the crystal phase structure of anatase-TiO2 to rutile, resulting in an increase of surface defect sites. The acidity of Ru-Sn/TiO2 catalyst was higher than that of Ru/TiO2 catalyst and the Lewis acid would increase with the formation of SnOTi, while RuO2 was mainly the Brönsted acid center, so it had a suitable B/L ratio. CO2 was almost the only carbon-containing product, the oxidation processproducts were mainly benzoquinone, maleate, acetate, aldehydes and other intermediates. Most chlorine species were removed as HCl and Cl2 under the promotion of Deacon reaction.

Insights into Chlorobenzene Catalytic Oxidation over Noble Metal Loading {001}-TiO2: The Role of NaBH4 and Subnanometer Ru Undergoing Stable Ru0↔Ru4+ Circulation.

Catalytic combustion of ubiquitous chlorinated volatile organic compounds (CVOCs) encounters bottlenecks regarding catalyst deactivation by chlorine poisoning and generation of toxic polychlorinated byproducts. Herein, Ru, Pd, and Rh were loaded on {001}-TiO2 for thermal catalytic oxidation of chlorobenzene (CB), with Ru/{001}-TiO2 representing superior reactivity, CO2 selectivity, and stability in the 1000 min on-stream test. Interestingly, both acid sites and reactive active oxygen species (ROS) were remarkably promoted via adding NaBH4. But merely enhancing these active sites of the catalyst in CVOC treatment is insufficient. Continuous deep oxidation of CB with effective Cl desorption is also a core issue successfully tackled through the steady Ru0↔Ru4+ circulation. This circulation was facilitated by the observed higher subnanometer Ru dispersion on {001}-TiO2 than the other two noble metals that was supported by single atom stability DFT calculation. Nearly 88 degradation products in off-gas were detected, with Ru/{001}-TiO2 producing the lowest polychlorinated benzene byproducts. An effective and sustainable CB degradation mechanism boosted by the cooperation of NaBH4 enhanced active sites and Ru circulation was proposed accordingly. Insights gained from this study open a new avenue to the rational design of promising catalysts for the treatment of CVOCs.

Solid oxide fuel cells (SOFCs) fed with biogas containing hydrogen chloride traces: Impact on direct internal reforming and electrochemical performance

This study is particularly aimed at investigating the influence of hydrogen chloride traces in biogas on direct internal reforming in solid oxide fuel cells (SOFCs). The experiments are performed with simulated biogas containing methane to carbon dioxide ratio of 3:2, the usual average proportion in biogas. To the best of our knowledge, there are no reported studies that investigated the effect of hydrogen chloride on direct internal reforming by clearly establishing the effect of reforming with outlet gas composition measurements. The experiments at SOFC operating temperature of 850 °C reveals no negative effect on reforming or cell performance, with 4, 8, and 12 ppm(v) of hydrogen chloride in biogas. At 800 °C, there is no visible performance degradation, but a negligible amount of methane (∼ 1%) is detected in the anode off gas. Both the reforming and electrochemical performance are marginally affected at 750 °C. Further, post-test analyses (FESEM-EDS, XRD) of the used SOFC reveals no damage to the cell at microstructure level or chlorine poisoning. All the experiments are performed in the context of utilizing the biogas generated from sewage treatment plants in an SOFC system. The reported level of chlorine traces in biogas generated from sewage sludge is < 10 ppm(v) and hence the limit set for experiments is at par with this value.

Chlorine poisoning caused by improper mixing of household disinfectants during the COVID-19 pandemic: Case series.

BACKGROUNDMisuse of disinfectants during the coronavirus disease 2019 pandemic has led to several poisoning incidents. However, there are few clinical case reports on poisoning caused by improper mixing of household disinfectants. AIMTo summarize the clinical characteristics and treatment effects of chlorine poisoning caused by improper mixing of hypochlorite bleach with acidic cleaning agents.METHODSWe retrospectively analyzed baseline and clinical data, clinical symptoms, and treatment methods of seven patients with chlorine poisoning who were admitted to the National Army Poisoning Treatment Center. RESULTSAmong the seven patients, the average poisoning time (exposure to admission) was 57 h (4-240 h). All patients were involved in cleaning bathrooms. Chest computed tomography scans revealed bilateral lung effusions or inflammatory changes in five patients. The partial pressure of oxygen decreased in six patients, and respiratory failure occurred in one. Five patients had different degrees of increase in white blood cell count. Humidified oxygen therapy, non-invasive mechanical ventilation, anti-inflammatory corticosteroids, antioxidants, and antibiotics were administered for treatment. The average length of hospital stay was 7 d (4-9 d). All seven patients recovered and were discharged. CONCLUSIONImproper mixing of household disinfectants may cause damage to the respiratory system due to chlorine poisoning. Corticosteroids may improve lung exudation in severe cases, and symptomatic supportive treatment should be performed early.

Mechanistic insights into the role of acidity to activity and anti-poisoning over Nb based catalysts for CVOCs combustion

A series of Nb-based catalysts with different acid types of carriers (TiO2, Beta molecular sieve, and CeO2) were synthesized. In the catalytic oxidation of dichloromethane (DCM), Nb/CeO2 exhibited the best catalytic activity, resistance to chlorine poisoning/carbon deposits, and stability, due to the abundant acid sites and appropriate ratio of Lewis to Bronsted acid sites on the surface. Both Lewis and Bronsted acid sites could participate in the breakdown of C-Cl bonds, whereas the former exerted a greater influence. The Bronsted acid sites participated in the desorption of Cl species, and were prone to the generation of carbon deposits. The chlorine species easily accumulated at the Lewis acid sites of Nb/TiO2(containing predominantly Lewis acid sites), formed metal chlorides, and caused chlorine poisoning. Carbon deposits made it difficult for Nb/Beta (containing predominantly Bronsted acid sites) to maintain long-term activity. Additionally, the acid sites generated by the active component were more important for DCM degradation than those generated by the carrier.

Development of an LC-MS/MS method for quantification of 3-chloro-L-tyrosine as a candidate marker of chlorine poisoning.

A simple and sensitive liquid chromatography coupled with electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method for the determination of 3-chloro-L-tyrosine (Cl-Tyr) was developed and validated. For sample preparation, 50μL of the body fluids or tissue extracts were processed by protein precipitation followed by the derivatization with dansyl chloride. The calibration curve was linear over the concentration range of 2.0-200ng/mL blood or 4.0-400ng/g tissue. Our method allowed the reproducible and accurate quantification. That is, the intra- and inter-assay coefficients of variation were below 7.73 and 6.94%, respectively in both the blood and lung. We applied the developed method to the analysis of Cl-Tyr in the human autopsy samples, which were suspected of chlorine poisoning, and detected 55.2ng/mL and 206.6ng/g Cl-Tyr in left heart blood and lung, respectively. Furthermore, in more than 20 autopsy samples, which were obtained from other causes of death including burn, drowning, hanging, internal disease, trauma and drug poisoning, Cl-Tyr was almost not detected in their both body fluids and organ tissues. In conclusion, the data here reported demonstrate that the LC/ESI-MS/MS method allows the Cl-Tyr in the autopsy samples and that chlorine exposure strongly affects its level, providing a basis for novel identification tool of chlorine poisoning.

Toxic Myocardial Injury in a Patient With Coronary Atherosclerosis, Caused by Acute Poisoning With Gaseous Chlorine

Acute chlorine gas poisoning leads to activation of the sympathetic nervous system and, as a consequence, dysfunction of the cardiovascular system (CVS). We report a clinical case of toxic myocardial injury with gaseous chlorine. In a man with coronary artery disease and polypathy, toxic myocardial injury mimicked acute coronary syndrome (ACS) and was accompanied by a large area of left ventricular microvascular dysfunction, which did not coincide with the areas of blood supply of altered coronary arteries; the dynamics of electrocardiographic changes resembled myocardial stunning in Takotsubo syndrome (TS). The effect of chlorine on CVS, features of clinical and instrumental diagnostics and differentiation of primary / secondary CT and ACS are discussed.

Silicotungstic acid modified CeO2 catalyst with high stability for the catalytic combustion of chlorobenzene

The catalysts’ redox capacity and surface acidity was important during the catalytic combustion of chlorobenzene (CB). CeO2 showed great attractiveness due to its high oxygen storage capacity. Furthermore, the increase of acidity on the catalyst surface could improve the resistance to the chlorine poisoning. In this work, the silicotungstic (HSiW) modified CeO2 catalysts prepared by four cerium salts and exhibited the different morphologies and catalytic activity. The HSiW modified CeO2 catalyst prepared by Ce(CH3COO)3 (Cat-A) exhibited the best catalytic activity due to its abundant surface weak acid sites, more Ce3+ species and surface adsorption oxygen. The HSiW mainly located on the CeO2 (111) planes of the Cat-A, which was conducive to redox property of CeO2, thus promoting the deep oxidation of CB. Meanwhile the redox ability together with the weak acidity influenced the catalytic efficiency at low temperature. And the redox ability played a major role at high temperature. In addition, the Cat-A still possessed high stability and water resistance and maintained high activity after continuous catalytic oxidation of CB at 235 and 295 °C for 100h, exhibiting the possibility of industrial application.

The positive effect of Ca2+ on cryptomelane-type octahedral molecular sieve (K-OMS-2) catalysts for chlorobenzene combustion

Herein, K-OMS-2 catalysts with different levels of Ca2+ loading were synthesized to investigate the influence of Ca2+ deposition on the catalytic oxidation of CB. The micromorphology, redox ability, oxygen species, and surface acidity of the prepared catalysts were analyzed via SEM, HR-TEM, H2-TPR, O2-TPD, Py-IR, and GC–MS. After the Ca addition, CB conversion on the catalyst was achieved at <220 °C and the polychlorinated by-product yield decreased significantly. Although CaCO3 formation on the catalyst surface from Ca2+ caused a decline in number and fluidity of the surface lattice oxygen species, no significant impact on surface adsorbed oxygen species content was observed. Furthermore, CaCO3 reacted with dissociated chlorine species (HCl and polychlorinated products generated in situ), which inhibited chlorine poisoning of the active phase.

Y-Modified MCM-22 Supported PdOx Nanocrystal Catalysts for Catalytic Oxidation of Toluene

A series of rare earth elements (REEs)-modified and Mobil Composition of Matter (MCM)-22-supported Pd nanocrystal catalysts were synthesized via a high-temperature solution-phase reduction method and tested for toluene complete oxidation. These catalytic materials were systematically characterized by N2 adsorption/desorption, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive spectroscopy (EDS), inductively coupled plasma atomic emission spectroscopy (ICP-AES), temperature-programmed surface reaction of toluene (toluene-TPSR) and X-ray photoelectron spectroscopic (XPS) techniques in order to investigate the structure–catalytic property relationship. Moreover, catalysts with an appropriate yttrium content greatly improved the catalytic activity of 0.2%Pd/MCM-22. PdOx (x = 0, 1) nanoparticles, ranging from 3.6 to 6.8 nm, which were well distributed on the surface of MCM-22. Efficient electron transfer from the Pd2+/Pd0 redox cycle facilitated the catalytic oxidation process, and the formation of Pd (or Y) –O–Si bonds improved the high dispersion of the PdOx and Y2O3 particles. Toluene–TPSR experiments suggested that the addition of Y2O3 improved the physical/chemical adsorption of 0.2%Pd/MCM-22, thus increasing the toluene adsorption capacity. Then, 0.2%Pd/7.5%Y/MCM-22 exhibited the highest catalytic performance. In addition, this catalyst maintained 95% conversion with high resistance to water and chlorine poisoning, even after toluene oxidation at 210 °C for 100 h, making it more valuable in practical applications.