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1.
ACS Appl Mater Interfaces ; 16(35): 46384-46391, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39179524

RESUMO

The electrochemical nitric oxide reduction reaction (NORR), which utilizes water as the sole hydrogen source, has the potential to facilitate ammonia production while concurrently mitigating pollutants. However, limited research has been dedicated to characterizing the structure of interfacial water due to the challenges associated with probing this intricate system, impeding the development of more efficient catalysts for the NORR process. Herein, the Cu2O microcrystals with distinct exposed facets, including {100}, {110}, and {111}, are employed for the model catalysts to investigate interfacial water structure and intermediate species in the NORR process. The results from shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) indicated that the NORR performance in 0.1 M Na2SO4 (with heavy water as the solvent) was positively correlated to the proportion of hydrated Na+ ion water. In addition, a sequence of intermediates from the NORR, including *NOH, *NH, *NH2, and *NH3, was detected by employing a combination of multiple in situ characterization methods. Furthermore, in conjunction with experimental results and theoretical calculations, we revealed the potential reaction pathway of NORR. This study offers novel insights into the NORR mechanism and valuable guidance for the design of high-performance catalysts for ammonia production.

2.
Int J Biol Sci ; 20(10): 3773-3783, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39113707

RESUMO

Colorectal cancer (CRC) is a common malignant tumor associated with high morbidity and mortality. Despite an increase in early screening and treatment options, people with CRC still have a poor prognosis and a low 5-year survival rate. Therefore, mining more therapeutic targets and developing means of early diagnosis and determining prognosis are now imperative in the clinical treatment of CRC. Ferroptosis is a recently identified type of regulated cell death (RCD) characterized, which is identified by the accumulation of iron-dependent lipid peroxidation, thereby causing membrane damage and cell death. Recent studies have shown that ferroptosis is associated with tumors, including CRC, and can be involved in CRC progression; however, the underlying mechanisms are complex and heterogeneous and have not been thoroughly summarized. Therefore, this study reviewed the roles of ferroptosis in CRC progression to target ferroptosis-related factors for CRC treatment. The significance of ferroptosis-related biomarkers and genes in the early diagnosis and prognosis of CRC was also investigated. Furthermore, the limitations of ferroptosis studies in the current treatment of CRC, as well as future research perspectives, are discussed.


Assuntos
Neoplasias Colorretais , Ferroptose , Humanos , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Neoplasias Colorretais/mortalidade , Peroxidação de Lipídeos , Prognóstico , Animais , Biomarcadores Tumorais/metabolismo
3.
Clin Transl Oncol ; 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39167272

RESUMO

The process by which living cells are phagocytosed and digested to death is called cell death by phagocytosis, a term that has just recently been generalized and redefined. It is characterized by the phagocytosis of living cells and the cessation of cell death by phagocytosis. Phagocytosis of dead cells is a widely discussed issue in cancer, cell death by phagocytosis can stimulate phagocytosis and stimulate adaptive immunity in tumors, and at the same time, do not-eat-me signaling is an important site for cancer cells to evade recognition by phagocytes. Therefore, we discuss in this review cell death by phagocytosis occurring in cancer tissues and emphasize the difference between this new concept and the phagocytosis of dead tumor cells. Immediately thereafter, we describe the mechanisms by which cell death by phagocytosis occurs and how tumors escape phagocytosis. Finally, we summarize the potential clinical uses of cell death by phagocytosis in tumor therapy and strive to provide ideas for tumor therapy.

4.
Int Immunopharmacol ; 137: 112537, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-38909493

RESUMO

Colorectal cancer (CRC) has been one of the most common malignancies worldwide. Despite the advances in current therapies, the mortality rate of CRC remains high. Among them, immunotherapy has achieved satisfactory results in some CRC patients, however, how to expand the use of immunotherapy in CRC patients remains an urgent challenge. Surprisingly, the intratumoral microbiota has been found in multiple tumor tissues, including CRC. It has been demonstrated that the intratumoral microbiota is associated with the progression and treatment of CRC, and is able to enhance or decrease anti-tumor immune responses via different mechanisms as well as influence the immunotherapy efficacy, providing new potential therapeutic targets for CRC immunotherapy. In this review, we focus on the characteristics of the intratumoral microbiota, its roles in the genesis and development of CRC, its modulation of anti-tumor immune responses and immunotherapy, and propose potential applications of the intratumoral microbiota in CRC immunotherapy. Additionally, we propose possible directions for future research on the intratumoral microbiota related to CRC immunotherapy.


Assuntos
Neoplasias Colorretais , Imunoterapia , Humanos , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/terapia , Neoplasias Colorretais/microbiologia , Imunoterapia/métodos , Animais , Microbiota/imunologia , Microambiente Tumoral/imunologia , Microbioma Gastrointestinal/imunologia
5.
Bioorg Chem ; 150: 107594, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38941701

RESUMO

Inhibition of human dihydroorotate dehydrogenase (hDHODH) represents a promising strategy for suppressing the proliferation of cancer cells. To identify novel and potent hDHODH inhibitors, a total of 28 piperine derivatives were designed and synthesized. Their cytotoxicities against three human cancer cell lines (NCI-H226, HCT-116, and MDA-MB-231) and hDHODH inhibitory activities were also evaluated. Among them, compound H19, exhibited the strongest inhibitory activities (NCI-H226 IC50 = 0.95 µM, hDHODH IC50 = 0.21 µM). Further pharmacological investigations revealed that H19 exerted anticancer effects by inducing ferroptosis in NCI-H226 cells, with its cytotoxicity being reversed by ferroptosis inhibitors. This was supported by the intracellular growth or decline of ferroptosis markers, including lipid peroxidation, Fe2+, GSH, and 4-HNE. Overall, H19 emerges as a promising hDHODH inhibitor with potential anticancer properties warranting development.


Assuntos
Alcaloides , Antineoplásicos , Benzodioxóis , Proliferação de Células , Di-Hidro-Orotato Desidrogenase , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos , Ferroptose , Piperidinas , Alcamidas Poli-Insaturadas , Humanos , Alcaloides/farmacologia , Alcaloides/química , Alcaloides/síntese química , Di-Hidro-Orotato Desidrogenase/antagonistas & inibidores , Piperidinas/farmacologia , Piperidinas/química , Piperidinas/síntese química , Benzodioxóis/farmacologia , Benzodioxóis/síntese química , Benzodioxóis/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/síntese química , Relação Estrutura-Atividade , Ferroptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Alcamidas Poli-Insaturadas/farmacologia , Alcamidas Poli-Insaturadas/química , Alcamidas Poli-Insaturadas/síntese química , Estrutura Molecular , Relação Dose-Resposta a Droga , Descoberta de Drogas , Linhagem Celular Tumoral
6.
Microbiol Res ; 285: 127777, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38797111

RESUMO

Immunotherapies currently used in clinical practice are unsatisfactory in terms of therapeutic response and toxic side effects, and therefore new immunotherapies need to be explored. Intratumoral microbiota (ITM) exists in the tumor environment (TME) and reacts with its components. On the one hand, ITM promotes antigen delivery to tumor cells or provides cross-antigens to promote immune cells to attack tumors. On the other hand, ITM affects the activity of immune cells and stromal cells. We also summarize the dialog pathways by which ITM crosstalks with components within the TME, particularly the interferon pathway. This interaction between ITM and TME provides new ideas for tumor immunotherapy. By analyzing the bidirectional role of ITM in TME and combining it with its experimental and clinical status, we summarized the adjuvant role of ITM in immunotherapy. We explored the potential applications of using ITM as tumor immunotherapy, such as a healthy diet, fecal transplantation, targeted ITM, antibiotics, and probiotics, to provide a new perspective on the use of ITM in tumor immunotherapy.


Assuntos
Imunoterapia , Neoplasias , Microambiente Tumoral , Microambiente Tumoral/imunologia , Imunoterapia/métodos , Humanos , Neoplasias/terapia , Neoplasias/imunologia , Microbiota/imunologia , Animais , Probióticos/administração & dosagem , Probióticos/uso terapêutico , Transplante de Microbiota Fecal
7.
BMC Med ; 22(1): 218, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38816877

RESUMO

BACKGROUND: Deep brain stimulation (DBS) is a promising therapy for refractory Gilles de la Tourette syndrome (GTS). However, its long-term efficacy, safety, and recommended surgical age remain controversial, requiring evidence to compare different age categories. METHODS: This retrospective cohort study recruited 102 GTS patients who underwent DBS between October 2006 and April 2022 at two national centers. Patients were divided into two age categories: children (aged < 18 years; n = 34) and adults (aged ≥ 18 years; n = 68). The longitudinal outcomes as tic symptoms were assessed by the YGTSS, and the YBOCS, BDI, and GTS-QOL were evaluated for symptoms of obsessive-compulsive disorder (OCD), depression, and quality of life, respectively. RESULTS: Overall, these included patients who finished a median 60-month follow-up, with no significant difference between children and adults (p = 0.44). Overall, the YGTSS total score showed significant postoperative improvements and further improved with time (improved 45.2%, 51.6%, 55.5%, 55.6%, 57.8%, 61.4% after 6, 12, 24, 36, 48, and ≥ 60 months of follow-up compared to baseline, respectively) in all included patients (all p < 0.05). A significantly higher improvement was revealed in children than adults at ≥ 60 months of follow-up in the YGTSS scores (70.1% vs 55.9%, p = 0.043), and the time to achieve 60% improvement was significantly shorter in the children group (median 6 months vs 12 months, p = 0.013). At the last follow-up, the mean improvements were 45.4%, 48.9%, and 55.9% and 40.3%, 45.4%, and 47.9% in YBOCS, BDI, and GTS-QOL scores for children and adults, respectively, which all significantly improved compared to baseline (all p < 0.05) but without significant differences between these two groups (all p > 0.05), and the children group received significantly higher improvement in GTS-QOL scores than adults (55.9% vs. 47.9%, p = 0.049). CONCLUSIONS: DBS showed acceptable long-term efficacy and safety for both children and adults with GTS. Surgeries performed for patients younger than 18 years seemed to show acceptable long-term efficacy and safety and were not associated with increased risks of loss of benefit compared to patients older than 18 at the time of surgery. However, surgeries for children should also be performed cautiously to ensure their refractoriness and safety.


Assuntos
Estimulação Encefálica Profunda , Síndrome de Tourette , Humanos , Síndrome de Tourette/terapia , Estimulação Encefálica Profunda/métodos , Masculino , Feminino , Criança , Adulto , Adolescente , Estudos Retrospectivos , Seguimentos , Adulto Jovem , Resultado do Tratamento , Qualidade de Vida , Pessoa de Meia-Idade , Fatores Etários
8.
Cell Biochem Funct ; 42(3): e3999, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38571320

RESUMO

Intratumoral microbiota (ITM) are microorganisms present in tumor cells. ITM participate in tumor development by affecting tumor cells directly and the tumor microenvironment (TME), indirectly. Alterations in ITM instigate changes in tumor DNA, activate oncogenic pathways, induce tumor inflammatory responses, disrupt normal immune activity, and facilitate the secretion of effectors leading to tumor progression, metastasis, or diminished therapeutic effects. ITM varies significantly in different types of cancer cells and disease states. The presence of certain ITM serves as a predictor of various disease states. Thus, ITM predicts tumorigenesis, tumor grade, treatment efficacy, and prognosis, making it a potential tumor biomarker. The present study aimed to determine the mechanisms by which ITM affects tumor development, especially through the TME; highlight the significant potential of ITM in enhancing tumor diagnosis and prognosis; and outline future directions for ITM research, with a focus on the development of innovative tumor markers.


Assuntos
Neoplasias , Humanos , Neoplasias/diagnóstico , Carcinogênese , Microambiente Tumoral
9.
Cell Commun Signal ; 22(1): 232, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637851

RESUMO

Metastasis poses a major challenge in colorectal cancer (CRC) treatment and remains a primary cause of mortality among patients with CRC. Recent investigations have elucidated the involvement of disrupted gut microbiota homeostasis in various facets of CRC metastasis, exerting a pivotal influence in shaping the metastatic microenvironment, triggering epithelial-mesenchymal transition (EMT), and so on. Moreover, therapeutic interventions targeting the gut microbiota demonstrate promise in enhancing the efficacy of conventional treatments for metastatic CRC (mCRC), presenting novel avenues for mCRC clinical management. Grounded in the "seed and soil" hypothesis, this review consolidates insights into the mechanisms by which imbalanced gut microbiota promotes mCRC and highlights recent strides in leveraging gut microbiota modulation for the clinical prevention and treatment of mCRC. Emphasis is placed on the considerable potential of manipulating gut microbiota within clinical settings for managing mCRC.


Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Microbioma Gastrointestinal , Humanos , Neoplasias Colorretais/patologia , Microambiente Tumoral
11.
Asian J Psychiatr ; 94: 103960, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38368692

RESUMO

OBJECTIVES: To evaluate the efficacy and safety of combined deep brain stimulation (DBS) with capsulotomy for comorbid motor and psychiatric symptoms in patients with Tourette's syndrome (TS). METHODS: This retrospective cohort study consecutively enrolled TS patients with comorbid motor and psychiatric symptoms who were treated with combined DBS and anterior capsulotomy at our center. Longitudinal motor, psychiatric, and cognitive outcomes and quality of life were assessed. In addition, a systematic review and meta-analysis were performed to summarize the current experience with the available evidence. RESULTS: In total, 5 eligible patients in our cohort and 26 summarized patients in 6 cohorts were included. After a mean 18-month follow-up, our cohort reported that motor symptoms significantly improved by 62.4 % (P = 0.005); psychiatric symptoms of obsessive-compulsive disorder (OCD) and anxiety significantly improved by 87.7 % (P < 0.001) and 78.4 % (P = 0.009); quality of life significantly improved by 61.9 % (P = 0.011); and no significant difference was found in cognitive function (all P > 0.05). Combined surgery resulted in greater improvements in psychiatric outcomes and quality of life than DBS alone. The synthesized findings suggested significant improvements in tics (MD: 57.92, 95 % CI: 41.28-74.56, P < 0.001), OCD (MD: 21.91, 95 % CI: 18.67-25.15, P < 0.001), depression (MD: 18.32, 95 % CI: 13.26-23.38, P < 0.001), anxiety (MD: 13.83, 95 % CI: 11.90-15.76, P < 0.001), and quality of life (MD: 48.22, 95 % CI: 43.68-52.77, P < 0.001). Individual analysis revealed that the pooled treatment effects on motor symptoms, psychiatric symptoms, and quality of life were 78.6 %, 84.5-87.9 %, and 83.0 %, respectively. The overall pooled rate of adverse events was 50.0 %, and all of these adverse events were resolved or alleviated with favorable outcomes. CONCLUSIONS: Combined DBS with capsulotomy is effective for relieving motor and psychiatric symptoms in TS patients, and its safety is acceptable. However, the optimal candidate should be considered, and additional experience is still necessary.


Assuntos
Estimulação Encefálica Profunda , Transtorno Obsessivo-Compulsivo , Síndrome de Tourette , Humanos , Síndrome de Tourette/terapia , Síndrome de Tourette/cirurgia , Estimulação Encefálica Profunda/efeitos adversos , Estimulação Encefálica Profunda/métodos , Masculino , Adulto , Feminino , Transtorno Obsessivo-Compulsivo/terapia , Transtorno Obsessivo-Compulsivo/cirurgia , Estudos Retrospectivos , Adulto Jovem , Terapia Combinada , Adolescente , Cápsula Interna/cirurgia , Comorbidade , Qualidade de Vida , Resultado do Tratamento , Avaliação de Resultados em Cuidados de Saúde
12.
J Colloid Interface Sci ; 660: 800-809, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38277837

RESUMO

Electrocatalytic hydrogenation (ECH) reduction provides an environment-friendly alternative to conventional method for the upgrade of furfural to furfuryl alcohol. At present, exploring superior catalysts with high activity and selectivity, figuring out the reduction mechanism in aqueous alkaline environment are urgent. In this work, zinc cobalt bimetallic oxide (ZnMn2O4) with surface-derived Zn2+ vacancies supported by carbon nanofibers (d-ZnMn2O4-C) was fabricated. The d-ZnMn2O4-C exhibited excellent performance in electrocatalytic reduction of furfural, high furfuryl alcohol yield (49461.1 ± 228 µmol g-1) and Faradaic efficiency (95.5 ± 0.5 %) was obtained. In-depth research suggested that carbon nanofiber may strongly promoted the production of adsorbed hydrogen (Hads), and Zn2+ vacancies may significantly lowered the energy barrier of furfural reduction to furfuryl alcohol, the synergistic effect between carbon nanofiber and d-ZnMn2O4 probably facilitated the reaction between Hads and furfuryl alcohol radical, thereby promoting the formation of furfuryl alcohol. Furthermore, the reaction mechanism was clarified by inhibitor coating and isotope experiments, the results of which revealed that the conversion of furfural to furfuryl alcohol on d-ZnMn2O4-C followed both ECH and direct electroreduction mechanism.

13.
ACS Appl Mater Interfaces ; 16(5): 5735-5744, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38271590

RESUMO

Efficiently upgrading 5-hydroxymethylfurfural (HMF) into high-value-added products, such as 2,5-diformylfuran (DFF) and 2,5-furan dicarboxylic acid (FDCA), through a photocatalytic process by using solar energy has been incessantly pursued worldwide. Herein, a series of transition-metal (TM = Ni, Fe, Co, Cu) single atoms were supported on Ti4+αTi3+1-αO2-δ nanofibers (NFs) with certain defects (Ov), denoted as TM SAC-Ti4+αTi3+1-αO2-δ NFs (TM = Ni, Fe, Co, Cu), aiming to enhance the photocatalytic conversion of HMF. A super HMF conversion rate of 57% and a total yield of 1718.66 µmol g-1 h-1 (DFF and FDCA) surpassing that of the Ti4+αTi3+1-αO2-δ NFs by 1.6 and 2.1 times, respectively, are realized when TM is Co (Co SAC-Ti4+αTi3+1-αO2-δ NFs). Experiments combined with density functional theory calculation (DFT) demonstrate that the TM single atoms occupy the Ti site of Ti4+αTi3+1-αO2-δ NFs, which plays a dominant role in the photo-oxidation of HMF. Raman, X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR) characterizations confirm the strong electron local exchange interaction in TM SAC-Ti4+αTi3+1-αO2-δ NFs and demonstrate the substitution of Ti by the TM SACs. The projected density of states and charge density difference reveal that the strong interaction between metal-3d and O-2p orbitals forms Ti-O-TM bonds. The bonds are identified as the adsorption site, where TM single atoms on the surface of Ti4+αTi3+1-αO2-δ NFs reduce HMF molecule adsorption energy (Eads). Furthermore, the TM single atom modulates the electronic structure of TM SAC-Ti4+αTi3+1-αO2-δ NFs through electron transfer, leading to narrow band gaps of the photocatalysts and enhancing their photocatalytic performance. This study has uncovered a newer strategy for enhancing the photocatalytic attributes of semiconducting materials.

14.
J Cancer Res Clin Oncol ; 149(14): 13477-13494, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37491636

RESUMO

Cancer immunotherapy has emerged as a groundbreaking method of treating malignancies. However, cancer immunotherapy can only benefit a small percentage of patients, and the numerous side effects that might develop during treatment reduce its effectiveness or even put patients' lives in jeopardy. Surprisingly, the gut microbiome Akkermansia muciniphila (A. muciniphila) can significantly inhibit carcinogenesis and improve anti-tumor effects, thus increasing the effectiveness of cancer immunotherapy and decreasing the likelihood of side effects. In this review, we focus on the effects of A. muciniphila on the human immune system and the positive impacts of A. muciniphila on cancer immunotherapy, which can build on strengths and improve weaknesses of cancer immunotherapy. The potential clinical applications of A. muciniphila on cancer immunotherapy are also proposed, which have great prospects for anti-tumor therapy.

15.
J Hazard Mater ; 457: 131743, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37270957

RESUMO

Microplastic pollution has emerged as a pressing environmental issue of global concern due to its detrimental effects on the environment and ecology. Restricted to their characters of complex composition, it is a great challenge to propose a more cost-effective approach to achieve highly selective conversion of microplastic into add-value products. Here we demonstrate an upcycling strategy for converting PET microplastics into added-value chemicals (formate, terephthalic acid and K2SO4). PET is initially hydrolyzed in KOH solution to produce terephthalic acid and ethylene glycol, which is subsequently used as an electrolyte to produce formate at the anode. Meanwhile, the cathode undergoes hydrogen evolution reaction to produce H2. Preliminary techno-economic analysis suggests that this strategy has certain economic feasibility and a novel Mn0.1Ni0.9Co2O4-δ rod-shaped fiber (RSFs) catalyst we synthesized can achieve high Faradaic efficiency (> 95%) at 1.42 V vs. RHE with optimistic formate productivity. The high catalytic performance can be attributed to the doping of Mn changing the electronic structure and reducing the metal-oxygen covalency of NiCo2O4, reducing the lattice oxygen oxidation in spinel oxide OER electrocatalysts. This work not only put forward an electrocatalytic strategy for PET microplastic upcycling but also guides the design of electrocatalysts with excellent performance.

16.
J Clin Med ; 12(5)2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36902568

RESUMO

BACKGROUND: Electrode reconstruction for postoperative deep brain simulation (DBS) can be achieved manually using a surgical planning system such as Surgiplan, or in a semi-automated manner using software such as the Lead-DBS toolbox. However, the accuracy of Lead-DBS has not been thoroughly addressed. METHODS: In our study, we compared the DBS reconstruction results of Lead-DBS and Surgiplan. We included 26 patients (21 with Parkinson's disease and 5 with dystonia) who underwent subthalamic nucleus (STN)-DBS, and reconstructed the DBS electrodes using the Lead-DBS toolbox and Surgiplan. The electrode contact coordinates were compared between Lead-DBS and Surgiplan with postoperative CT and MRI. The relative positions of the electrode and STN were also compared between the methods. Finally, the optimal contact during follow-up was mapped onto the Lead-DBS reconstruction results to check for overlap between the contacts and the STN. RESULTS: We found significant differences in all axes between Lead-DBS and Surgiplan with postoperative CT, with the mean variance for the X, Y, and Z coordinates being -0.13, -1.16, and 0.59 mm, respectively. Y and Z coordinates showed significant differences between Lead-DBS and Surgiplan with either postoperative CT or MRI. However, no significant difference in the relative distance of the electrode and the STN was found between the methods. All optimal contacts were located in the STN, with 70% of them located within the dorsolateral region of the STN in the Lead-DBS results. CONCLUSIONS: Although significant differences in electrode coordinates existed between Lead-DBS and Surgiplan, our results suggest that the coordinate difference was around 1 mm, and Lead-DBS can capture the relative distance between the electrode and the DBS target, suggesting it is reasonably accurate for postoperative DBS reconstruction.

17.
ACS Appl Mater Interfaces ; 15(10): 12915-12923, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36863000

RESUMO

Dichloromethane (CH2Cl2) hydrodechlorination to methane (CH4) is a promising approach to remove the halogenated contaminants and generate clean energy. In this work, rod-like nanostructured CuCo2O4 spinels with rich oxygen vacancies are designed for highly efficient electrochemical reduction dechlorination of dichloromethane. Microscopy characterizations revealed that the special rod-like nanostructure and rich oxygen vacancies can efficiently enhance surface area, electronic/ionic transport, and expose more active sites. The experimental tests demonstrated that CuCo2O4-3 with rod-like nanostructures outperformed other morphology of CuCo2O4 spinel nanostructures in catalytic activity and product selectivity. The highest methane production of 148.84 µmol in 4 h with a Faradaic efficiency of 21.61% at -2.94 V (vs SCE) is shown. Furthermore, the density function theory proved oxygen vacancies significantly decreased the energy barrier to promote the catalyst in the reaction and Ov-Cu was the main active site in dichloromethane hydrodechlorination. This work explores a promising way to synthesize the highly efficient electrocatalysts, which may be an effective catalyst for dichloromethane hydrodechlorination to methane.

19.
ACS Appl Mater Interfaces ; 15(9): 11885-11894, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36827641

RESUMO

Cobalt-manganese spinel catalysts performed unsatisfactory activity at low-temperature and narrow reaction temperature window, which greatly limited the application in NO reduction by CO. Herein, we synthesize a series of Cu-doped CoMn2O4 catalysts and apply to NO reduction by CO. The Cu0.3Co0.7Mn2O4 exhibited superior catalytic performance, reaching 100% NO conversion and 80% N2 selectivity at 250 °C. Detailed structural analysis showed that the introduced Cu replaces some Co in tetrahedral coordination to induce a strong synergistic effect between different metals. This endows the catalyst with the promotion of both electron transfer and oxygen vacancy generation on the catalyst surface. Importantly, the reaction mechanism and pathway were further revealed by in situ diffusion Fourier transform infrared spectroscopy (DRIFTS) and density functional theory (DFT) calculations. The results indicated that the cycle of oxygen vacancy mainly determines the catalytic activity of NO reduction by CO. Notably, Cu doping significantly lowered the energy barrier of the rate-determining step (*CO + O → *Ov + CO2), facilitating the desorption of the CO2 and exposing the active sites for efficient NO reduction with CO. This work offers an effective way for designing the catalyst in NO reduction by CO and provides a reference for exploring the catalytic mechanism of the reaction.

20.
ACS Appl Mater Interfaces ; 15(5): 6631-6638, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36705573

RESUMO

CuFe2O4 spinel has been considered as a promising catalyst for the electrochemical reaction, while the nature of the crystal phase on its intrinsic activity and the kind of active site need to be further explored. Herein, the crystal phase-dependent catalytic behavior and the main active sites of CuFe2O4 spinel for electrochemical dechlorination of 1,2-dichloroethane are carefully studied based on the combination of experiments and theoretical calculations. Cubic and tetragonal CuFe2O4 are successfully prepared by a facile sol-gel method combined with high temperature calcination. Impressively, CuFe2O4 with the cubic phase shows a higher activity and ethylene selectivity compared to CuFe2O4 with the tetragonal phase, suggesting a significant facilitation of electrocatalytic performance by the cubic crystal structure. Moreover, the octahedral Fe atom on the surface of cubic CuFe2O4(311) is the active site responsible to produce ethylene with the energy barrier of 0.40 eV. This work demonstrates the significance of crystal phase engineering for the optimization of electrocatalytic performance and offers an efficient strategy for the development of advanced electrocatalysts.

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