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1.
Chemosphere ; 352: 141346, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38311035

ABSTRACT

Doping proves to be an efficacious method of establishing intermetallic interactions for enhancing toluene oxidation performance of bimetallic oxides. However, conventional bimetallic oxide catalysts are yet to overcome their inadequacy in establishing intermetallic interactions. In this work, the dispersion of Mn-Co bimetallic sites was improved by hydrolytic co-precipitation, strengthening the intermetallic interactions which improved the structural and physicochemical properties of the catalysts, thus significantly enhancing its catalytic behavior. MnCo-H catalysts fabricated by the hydrolytic co-precipitation method showed promising catalytic performance (T50 = 223 °C, T90 = 229 °C), robust stability (at least 100 h) and impressive water resistance (under 10 vol.% of water) for toluene elimination. Hydrolytic co-precipitation has been found to improve dispersion of MnCo elements and to enhance interaction between Co and Mn ions (Mn4+ + Co2+ = Mn3+ + Co3+), resulting in a lower reduction temperature (215 °C) and a weaker Mn-O bond strength, creating more lattice defects and oxygen vacancies, which are responsible for superior catalytic properties of MnCo-H samples. Furthermore, in situ DRIFTs showed that gaseous toluene molecules adsorbed on the surface of MnCo-H were continuously oxidized to benzyl alcohol → benzaldehyde → benzoate, followed by a ring-opening reaction with surface-activated oxygen to convert to maleic anhydride as the final intermediate, which further generates water and carbon dioxide. It was also revealed that the ring-opening reaction for the conversion of benzoic acid to maleic anhydride is the rate-controlling step. This study reveals that optimizing active sites and improving reactive oxygen species by altering the dispersion of bimetals to enhance bimetallic interactions is an effective strategy for the improvement of catalytic behavior, while the hydrolytic co-precipitation method fits well with this corollary.


Subject(s)
Manganese Compounds , Manganese , Nitrosourea Compounds , Toluene , Manganese/chemistry , Oxidation-Reduction , Toluene/chemistry , Maleic Anhydrides , Oxides/chemistry , Water , Cobalt/chemistry , Oxygen/chemistry , Catalysis
2.
Environ Res ; 248: 118411, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38316382

ABSTRACT

As a typical heterogeneous catalytic process, the catalytic combustion of toluene over Co3O4-based catalysts is strongly depends on the surface properties of catalysts, especially the concentration of surface oxygen defects. Here, a novel way was proposed to construct chemically bonded CuO-Co3O4 interface by chemical deposition of CuO onto Co3O4 nanoflowers. The interfacial refinement effect between CuO and Co3O4 support disrupted the ordered atomic arrangement and created countless unsaturated coordination sites at CuO-Co3O4 interface, inducing a significant generation of surface oxygen defects. Surface-rich oxygen vacancies enhanced the capacity of 20%CuO/Co3O4-R to adsorb and activate oxygen species. Benefiting from this, 90 % toluene conversion was reached at 228 °C over 20%CuO/Co3O4-R, which was much lower than that over 20%CuO/Co3O4-S prepared by impregnation method and CuO/Co3O4-mix obtained by mechanically mixing way. In-situ DRIFTS analysis revealed that toluene could be directly decomposed into benzaldehyde at the highly defective CuO-Co3O4 interface, leading to toluene oxidation following the path of toluene → benzaldehyde → benzoate → maleic anhydride → water and carbon dioxide over 20%CuO/Co3O4-R, which was significantly different from decomposition mechanism over 20%CuO/Co3O4-S. Additionally, 20%CuO/Co3O4-R displayed terrific recyclability and outstanding stability, showing good application potential.


Subject(s)
Benzaldehydes , Cobalt , Oxides , Oxygen , Oxidation-Reduction , Oxygen/chemistry , Toluene/analysis
3.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 26(3): 270-3, 283, 2014 Jun.
Article in Chinese | MEDLINE | ID: mdl-25345151

ABSTRACT

OBJECTIVE: To explore the status of depression in patients with advanced schistosomiasis and its influencing factors, so as to provide the evidence for improving psychological interventions. METHODS: A total of 206 patients with advanced schistosomiasis were investigated with the self-designed general information questionnaire, the Self-Rating Depression Scale, and WHOQOL-BREF Form. RESULTS: Among the 206 cases, the incidence of depression was 69.4%, and depression was negatively related to the quality of life (P = 0.000). The multiple logistic regression analysis showed that the times of hospitalization (ß = 0.442, P = 0.007) was a risk factor for depression, while the high education levels (ß = -0.583, P = 0.011) and the history of portal hypertension operation (ß = -0.917, P = 0.000) were the protective factors. CONCLUSION: The incidence of depression in advanced schistosomiasis patients is high, and it is influenced by various factors. Therefore, we should take corresponding interventions to reduce its occurrence.


Subject(s)
Depression/etiology , Schistosomiasis/psychology , Adult , Aged , Aged, 80 and over , Female , Hospitalization , Humans , Male , Middle Aged , Quality of Life , Schistosomiasis/therapy , Surveys and Questionnaires , Young Adult
4.
Article in Chinese | MEDLINE | ID: mdl-25856895

ABSTRACT

OBJECTIVE: To explore the design and application of psychological intervention paths for ascites type of advanced schistosomiasis patients. METHODS: A total of 156 ascites type of advanced schistosomiasis patients were divided into an intervention group and a control group with 78 cases each. A psychological intervention path table was designed in accordance with the psychological characteristics and demands of the advanced schistosomiasis patients. Five steps were used to guide the nurses involved to carry out the psychological intervention. RESULTS: Before the intervention, there were no statistically significant differences (all P > 0.05) between two groups in SAS, SDS, WHOQOL-BRER scores, but after the intervention, all the evaluation indexes improved in the intervention group and there were statistically significant differences between the intervention group and control group in SAS, SDS, WHOQOL-BRER scores (all P < 0.05). CONCLUSION: The application of psychological intervention paths for ascites type of advanced schistosomiasis patients can improve their negative emotions and qualities of life.


Subject(s)
Psychotherapy , Schistosomiasis/psychology , Schistosomiasis/therapy , Aged , Aged, 80 and over , Disease Progression , Female , Hospitalization , Humans , Male , Middle Aged , Psychological Tests , Schistosomiasis/pathology
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