Highly efficient K-doped Mn-Ce catalysts with strong K-Mn-Ce interaction for toluene oxidation

In this study,K_(x)-Mn-Ce catalysts prepared by sol-gel method were investigated for toluene oxidation.Compared with Mn-Ce,the catalytic performance of K_(x)-Mn-Ce was further improved.X-ray diffraction(XRD),high resolution transmission electron microscopy(HRTEM)and Raman analyses demonstrate that K ions enter the lattice of CeO_(2) and disperse uniformly.The results of X-ray photoelectron spectroscopy(XPS),H_(2)-temperature programmed reduction(H_(2)-TPR).and O_(2)-temperature programmed desorption(O_(2)-TPD)analyses indicate that there is a strong interaction between K,Mn and Ce;the charge co mpensation effect would be induced when K ions enter the lattice of CeO_(2),which leads to more oxygen vacancies due to the generation of more Ce^(3+).Toluene-TPD shows that K-doping enhances the activation ability of toluene.Among all catalysts,K0.1-Mn-Ce shows the highest concentration of Mn^(4+),Ce^(3+),Osur,and redox ability,resulting in higher low-temperature catalytic activity.Additionally,the results of stability and water resistance also prove that K0.1-Mn-Ce catalyst possesses excellent stability and water resistance.

Synergistic effect of F and triggered oxygen vacancies over F-TiO_(2) on enhancing NO ozonation

Oxidation-absorption technology is a key step for NOxremoval from low-temperature gas.Under the condition of low O_(3)concentration(O_(3)/NO molar ratio = 0.6), F-TiO_(2)(F-TiO_(2)), which is cheap and environmentally friendly, has been prepared as ozonation catalysts for NO oxidation. Catalytic activity tests performed at 120℃showed that the NO oxidation efficiency of F-TiO_(2)samples was higher than that of TiO_(2)(about 43.7%), and the NO oxidation efficiency of F-TiO_(2)-0.15 was the highest, which was 65.3%. Combined with physicochemical characteristics of catalysts and the analysis of active species, it was found that there was a synergistic effect between F sites and oxygen vacancies on F-TiO_(2), which could accelerate the transformation of monomolecular O_(3)into multi-molecule singlet oxygen(1O_(2)), thus promoting the selective oxidation of NO to NO_(2). The oxidation reaction of NO on F-TiO_(2)-0.15 follows the Eley-Rideal mechanism, that is, gaseous NO reacts with adsorbed O_(3)and finally form NO_(2).

RNA sequencing-based optimization of biological lipid droplets for sonodynamic therapy to reverse tumor hypoxia and elicit robust immune response

Mitochondria-targeted sonodynamic therapy(SDT)is a promising strategy to inhibit tumor growth and activate the anti-tumor immune responses.Identifying the mechanisms underlying mitochondria-targeted SDT,further optimizing its efficacy,developing novel sonosensitizer carriers with good biocompatibility pose major challenges to the clinical practice of SDT.In this study,we investigated the mechanisms of mitochondria-targeted SDT and demonstrated that it suppressed the mitochondrial electron transport chain(ETC)in pancreatic cancer cells through RNA-sequencing analysis.Based on these findings,we constructed the functional lipid droplets(LDs)(CPI-613/IR780@LDs),which combined mitochondria-targeted SDT with the tricarboxylic acid(TCA)cycle inhibitor CPI-613.CPI-613/IR780@LDs synergistically inhibited the TCA cycle and the ETC of mitochondrial aerobic respiration to reduce oxygen consumption and increase reactive oxygen species(ROS)generation at the tumor site,thus enhancing the efficacy of SDT in hypoxic pancreatic cancer.Moreover,the combination of mitochondria-targeted SDT and anti-PD-1 antibody exhibited excellent tumor inhibition and activated anti-tumor immune responses by increasing tumorinfiltrating CD8+T cells and reducing regulatory T cells,synergistically arresting the growth of both primary and metastatic pancreatic tumors.Meanwhile,lipid droplets are cell-derived biological carriers with natural mitochondrial targeting ability and can achieve efficient hydrophobic drug loading through active phagocytosis.Therefore,the functional lipid droplet-based SDT combined with anti-PD-1 antibody holds great potential in the clinical treatment of hypoxic pancreatic cancer.

Effect of interaction between different CeO_(2)plane and platinum nanoparticles on catalytic activity of Pt/CeO_(2)in toluene oxidation

The plane exposure of support vitally affects the catalytic performance of the catalyst.In this work,CeO_(2)nanorods((110)plane exposure),nano-octahedrons((111)plane exposure)and nano-cubes((100)plane exposure)were prepared as the supports of Pt/CeO_(2)samples to investigate the effect of CeO_(2)plane exposure on total toluene oxidation.Characterizations reveal that the(110)plane of CeO_(2)is more helpful to the dispersion of Pt species,followed by(111)face.The improved dispersion of Pt species can enhance the metal-supports interaction,which promotes the electron transfer of CeO_(2)carrier to Pt nanoparticles and the adsorption-activation of O_(2),thereby facilitating the total oxidation of toluene via the Langmuir-Hinshelwood(L-H)mechanism.Therefore,Pt/CeO_(2)-r(nanorods)sample expresses excellent catalytic performance of toluene oxidation.Finally,the procedure of toluene total oxidation was studied by in-situ diffuse reflectance infrared Fourier transform(DRIFT)spectroscopy.We expect that this work can contribute to the development of an effective sample for the decomposition of volatile organic compounds(VOCs).

Effects of synthesis methods on catalytic activities of CoOx–TiO2 for low-temperature NH3-SCR of NO

A series of cobalt doped TiO2（Co-TiO2） and Co Oxloaded TiO2（Co/TiO2） catalysts prepared by sol–gel and impregnation methods respectively were investigated on selective catalytic reduction with NH3（NH3-SCR） of NO. It was found that Co-TiO2 catalyst showed more preferable catalytic activity at low temperature range. From characterization results of XRD,TEM, Raman and FT-IR, Co species were proved to be doped into TiO2 lattice by replaced Ti atoms. After being characterized and analyzed by NH3-TPD, PL, XPS, EPR and DRIFTS, it was found that the better NH3-SCR activities of Co-TiO2 catalysts, compared with Co/TiO2 catalyst, were ascribed to the formation of more oxygen vacancies which further promoted the production of more superoxide ions（O-2）. The superoxide ions were crucial for the formation of low temperature SCR reaction intermediates（NO-3） by reacting with adsorbed NO molecule. Therefore, these aspects were responsible for the higher low temperature NH3-SCR activity of Co-TiO2 catalysts.

Revealing active species of CePO_(4)catalyst for selective catalytic reduction of NO_(x)with NH_(3)

Revealing the active species of the catalyst is conducive to the design of more efficient catalyst.Herein,we tried to demonstrate the roles of amorphous and crystalline structures on CePO_(4)catalyst during selective catalytic reduction(SCR)of NO_(x)by NH_(3).Higher calcination temperature promotes the transfer of amorphous structure to crystalline structure on the surface of CePO_(4).Both amorphous and crystalline CePO_(4)species on CePO-X samples can provide acid sites for NH_(3)adsorption,but the former can provide more acid sites.The superior redox property of surface amorphous CePO_(4)species contributes to its high NH_(3)-SCR activity at low temperature,but it also leads to the decrease of high temperature(>350℃)NH_(3)-SCR activity due to the oxidation of NH_(3).In contrast,crystalline CePO_(4)species shows high activity only at high temperature because of its poor redox property.Therefo re,it can be inferred that amo rphous and crystalline structures on CePO_(4)catalyst can be the efficient active species of NH_(3)-SCR at low and high temperature,respectively.