A confined growth strategy to construct 3DOM SiO_(2) nanoreactor insitu embedded Co_(3)O_(4) nanoparticles catalyst for the catalytic combustion of VOCs:Superior H_(2)O and SO_(2) resistance

SO_(2)poisoning is a common problem in the catalytic combustion of volatile organic compounds(VOCs).In this work,we took three-dimensionally ordered macroporous and mesoporous(3DOM)SiO_(2)as the nanoreactor to protect active sites from SO_(2)erosion in the catalytic combustion of benzene.Simultaneously,the confined growth of metal active nanoparticles in the multi-stage pore is also full of challenges.And we successfully confined Co_(3)O_(4)nanoparticles(NPs)in macroporous and mesoporous channels.Interestingly,the precursors’growth in the pore was controlled and nanoreactors with different pore sizes were prepared by adjusting the loading amount and preparation methods.It is discovered that the Co_(3)O_(4)NPs confined in 3DOM SiO_(2)nanoreactor showed superior sulfur and water resistance.Density functional theory(DFT)calculations verified that the Co-Si catalyst had high SO_(2)adsorption energy(-0.48 eV),which illustrated that SO_(2)was hard to attach to the surface of the Co-Si catalyst.The SiO_(2)nanoreactor had low SO_(2)adsorption energy(-5.15 eV),which indicated that SO_(2)was easily absorbed on SiO_(2)nanoreactor.This illustrated that the SiO_(2)nanoreactor could protect effectively active sites from SO_(2)erosion.

A novel 3D printed technology to construct a monolithic ultrathin nanosheets Co_(3)O_(4)/SiO_(2) catalyst for benzene catalytic combustion

In this study,a novel three-dimensional(3D)-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP(OMm=ordered macro–meso porous,AP=aluminum phosphate)monolithic catalyst was for the first time constructed successfully with the hierarchical Co-phyllosilicate ultrathin nanosheets growth on the surface of 3D printed ordered macropore–mesoporous SiO_(2)support.On the one hand,we discovered that the construction of ordered macropore–mesoporous structures is beneficial to the diffusion and adsorption of reactants,intermediates,and products.On the other hand,the formation of hierarchical Co-phyllosilicate ultrathin nanosheets could provide more active Co&+species,abundant acid sites,and active oxygen.The above factors are in favor of improving the catalytic performance of benzene oxidation,and then a 3D-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP catalyst exhibited the superior catalytic activity.To explore the effect of catalysts structure and morphology,various Co-based catalysts were also constructed.Simultaneously,the 3D-OMm-Co_(3)O_(4)/SiO_(2)-0.5AP catalyst has excellent catalytic performance,water resistance,and thermal stability in the catalytic combustion of benzene due to the strong interactions between Co&+species and SiO_(2)in the phyllosilicate.Therefore,this study proposes a new catalyst synthesis method through 3D printing,and presents considerable prospects for the removal of VOCs from industrial applications.

Synthesis of amine-pillar[5]arene porous adsorbent for adsorption of CO_(2)and selectivity over N_(2)and CH_(4)

A novel amine-modified pillar[5]arene bonded porous silica adsorbent(DETA-P5S)was designed to be applied to dynamic CO_(2)adsorption and selective separation of CO_(2)over N_(2)and CH_(4)gases mixture.The results demonstrated that reasonable introduction of DETA into the BE-P5 bonded silica support has sig nificantly increased the adsorption capacity of CO_(2).The DETA-P5S has the optimal adsorption capacity of 9.1 mmol/g with 5 vol%CO_(2)at 40℃.The main reason of this increased capacity could be attributed to the enhanced CO_(2)diffusion into porous adsorbent for its better dispersion in the pores of amine pillar[5]arene cavity and active site of DETA.Furthermore,the dynamic saturation adsorption capacitie of DETA-P5S were 7.11(0.37)and 6.18(0.44)mmol/g for CO_(2)/N_(2)and CO_(2)/CH_(4),respectively,both the ga mixtures showed high separation selectivity.Simultaneously,the DETA-P5S can maintain outstanding CO_(2)adsorption capacity after fifteen regeneration cycles.Consequently,the designed DETA-P5S could serve a a promising adsorbent for CO_(2)capture and storage.

Selective adsorption of silver ions from aqueous solution using polystyrene-supported trimercaptotriazine resin

Tdmercaptotriazine-functionalized polystyrene chelating resin was prepared and employed for the adsorption of Ag（I） from aqueous solution. The adsorbent was characterized according to the following techniques： Fourier transform infrared spectroscopy, elemental analysis, scanning electron microscopy and the Brunauer-Emmet-Teller method. The effects of initial Ag（I） concentration, contact time, solution pH and coexisting ions on the adsorption capacity of Ag（I） were systematically investigated. The maximum adsorption capacity of AgO） was up to 187.1 mg/g resin at pH 0.0 and room temperature. The kinetic experiments indicated that the adsorption rate of Ag（I） onto the chelating resin was quite fast in the first 60 rain and reached adsorption equilibrium after 360 min. The adsorption process can be well described by the pseudo second-order kinetic model and the equilibrium adsorption isotherm was closely fitted by the Langmuir model. Moreover, the chelating resin could selectively adsorb more Ag（I） ions than other heavy metal ions including： Cu（Ⅱ）, Zn（Ⅱ）, Ni（Ⅱ）, Pb（Ⅱ） and Cr（Ⅲ） during competitive adsorption in the binary metal species systems, which indicated that it was a highly selective adsorbent of Ag（I） from aqueous solution.

Near-infrared H_(2)O_(2)production via dual pathways of O_(2)reduction and H_(2)O oxidation

Hydrogen peroxide(H_(2)O_(2))is a chemical that is widely of interest in both environmental and energy fields.On the one hand,as a clean oxidant,H_(2)O_(2)has been commonly used in the field of bleaching,disinfection,and advanced oxidation processes.On the other hand,H_(2)O_(2)has also been explored as a liquid fuel alternative to H_(2)or fossil fuels in fuel cells due to its high energy density.However,the current industrial production of H_(2)O_(2)relies on the anthraquinone(AO)method that involves palladium-catalyzed hydrogenation-oxidation steps.