Synthesis of K-doped three-dimensionally ordered macroporous Mn_(0.5)Ce_(0.5)O_δ catalysts and their catalytic performance for soot oxidation

A series of K-doped Mn0.5Ce0.5Oδ （K-MCO） catalysts with three-dimensionally ordered macroporous （3DOM） structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibited well-defined 3DOM nanostructure, which consisted of extensive interconnecting networks of spherical voids. The effects of the calcination temperature and calcination time on the morphological characteristics and crystalline forms of the catalysts were systematically studied. The catalysts showed high catalytic activity for the combustion of soot. 3DOM 20% K-MCO-4h catalyst, in particular, showed the highest catalytic activity of all of the catalysts studied （e.g., Ts0 = 331 ~C and Smco2 = 95.3%）. The occurrence of structural and synergistic effects among the K, Mn, and Ce atoms in the catalysts was favorable for enhancing their catalytic activity towards the combustion of diesel soot. Furthermore, the temperatures required for the complete combustion of the soot （〈400 ℃） were well within the exhaust temperature range （175-400 ℃）, which means that the accumulated soot can be removed under the conditions of the diesel exhaust gas. These catalysts could therefore be used in numerous practical applications because they are easy to synthesize, exhibit high catalytic activity, and can be made from low cost materials.

Three-dimensionally Ordered Macroporous Phosphotungstic Acid/SiO2 for Efficient Catalytic Oxidative Desulfurization

Three-dimensionally ordered（3DOM） macroporous phosphotungstic acid/SiO_2（HPW/SiO_2） materials were prepared by using colloidal crystal as templates and applied for oxidative desulfurization（ODS） of the model fuel oil. The obtained HPW/SiO_2 materials were characterized through scanning electron microscopy, powder X-ray diffraction, N_2 sorption, and Fourier transform infrared spectroscopy. The results indicated that 3 DOM HPW/SiO_2 possessed hierarchical pore architectures which contained ordered macropores and disordered mesopores, with the Keggin type HPW embedded in the framework of pore structure. The removal rate of dibenzothiophene（DBT） could reach 100% under the optimum conditions, moreover. The performance was only slightly decreased for the regenerated catalyst after 7 cycles.

Three-dimensionally ordered macroporous CeO_2/Al_2O_3-supported Au nanoparticle catalysts: Effects of CeO_2 nanolayers on catalytic activity in soot oxidation

A series of catalysts consisting of three‐dimensionally ordered macroporous(3DOM)x‐CeO2/Al2O3‐supported Au nanoparticles(x=2,10,20,and40wt%)were successfully synthesized using a reduction‐deposition method.These catalysts were characterized using scanning electron microscopy,the Brunauer‐Emmett‐Teller method,X‐ray diffraction,transmission electron microscopy,ultraviolet‐visible spectroscopy,and temperature‐programmed reduction by H2.Au nanoparticles of mean particle size5nm were well dispersed and supported on the inner walls of uniform macropores.The3DOM structure improved the contact efficiency between soot and the catalyst.An Al‐Ce‐O solid solution was formed in the multilayer support,i.e.,x‐CeO2/Al2O3,by the incorporation of Al3+ions into the CeO2lattice,which resulted in the creation of extrinsic oxygen vacancies.Strong interactions between the metal(Au)and the support(Ce)increased the amount of active oxygen species,and this promoted soot oxidation.The catalytic performance in soot combustion was evaluated using a temperature‐programmed oxidation technique.The presence of CeO2nanolayers in the3DOM Au/x‐CeO2/Al2O3catalysts clearly improved the catalytic activities in soot oxidation.Among the prepared catalysts,3DOM Au/20%CeO2/Al2O3showed high catalytic activity and stability in diesel soot oxidation.

Three-dimensionally ordered macroporous cross-linked polystyrene incorporating functional group via hydrophilic spacer arm

A versatile and effective method for incorporating functional groups on the pore wall of three-dimensionally ordered macroporous cross-linked polystyrene（3DOM CLPS） by hydrophilic spacer arm has been investigated.The 3DOM CLPS with pore size 865 nm was prepared by sacrifice template method.The hydrophilic spacer arm（polyethylene glycol,molecular weight is 600） was grafted to the 3DOM CLPS via nucleophilic substitution reaction.The other side of active hydroxyl can be further converted into a lot of other functional groups.In this report,the chelating ligand 2-mercaptobenzothiazole（MBZ） group was introduced on the end of the PGE chain to evidence the versatile functionalization approach.The functionalized ordered macroporous materials were characterized by FT-IR,element analyzer,SEM.The results reveal that the pores were successfully bonded with 2-mercaptobenzothiazole groups via hydrophilic spacer arms and the original morphology of ordered macroporous materials were remained after functionalization.The MBZ group density is 0.052 mmol/m^2.The functionalized 3DOM CLPS are expected to application as heavy metal ions adsorbent.

Pore-filling Three-dimensionally Ordered Macroporous Polyimide Composite Proton Conducting Membranes

The silica opal templates were prepared from three silica colloids of different diameters of 230 nm, 500 nm and 1.5 mm by a filtration route. The large-scale stable opal template membranes after sintering the deposited SiO2 opal template can be successfully obtained by optimizing the pH value and NaCl concentration in silica colloidal solutions. The three-dimensionally ordered macroporous（3DOM） polyimide membranes without crack were fabricated by reproducing the structure of silica opal template. We prepared the pore-filling composite proton exchange membranes by filling the 3DOM structure with proton conducting organosilane sol. The result indicates that the composite membranes exhibit higher water uptake than pure filling organosilane gel. The proton conductivity increased with the increasing of pore cell in composite membranes.

Ultrasmall NiS_(2)Nanocrystals Embedded in Ordered Macroporous Graphenic Carbon Matrix for Efficiently Pseudocapacitive Sodium Storage

Sodium-ion hybrid capacitor(SIHC)is one of the most promising alternatives for large-scale energy storage due to its high energy and power densities,natural abundance,and low cost.However,overcoming the imbalance between slow Na^(+)reaction kinetics of battery-type anodes and rapid ion adsorption/desorption of capacitive cathodes is a significant challenge.Here,we propose the high-rate-performance NiS_(2)@OMGC anode material composed of monodispersed NiS_(2) nanocrystals(8.8±1.7 nm in size)and N,S-co-doped graphenic carbon(GC).The NiS_(2)@OMGC material has a three-dimensionally ordered macroporous(3DOM)morphology,and numerous NiS_(2) nanocrystals are uniformly embedded in GC,forming a core-shell structure in the local area.Ultrafine NiS_(2) nanocrystals and their nano-microstructure demonstrate high pseudocapacitive Na-storage capability and thus excellent rate performance(355.7 mAh/g at 20.0 A/g).A SIHC device fabricated using NiS_(2)@OMGC and commercial activated carbon(AC)cathode exhibits ultrahigh energy densities(197.4 Wh/kg at 398.8 W/kg)and power densities(43.9 kW/kg at 41.3 Wh/kg),together with a long life span.This outcome exemplifies the rational architecture and composition design of this type of anode material.This strategy can be extended to the design and synthesis of a wide range of high-performance electrode materials for energy storage applications.

Three-dimensional ordered macroporous perovskite-type La_(1-x)K_xNiO_3 catalysts with enhanced catalytic activity for soot combustion: the Effect of K-substitution

Three-dimensional ordered macroporous (3DOM) La1?xKxNiO3 perovskite-type catalysts were successfully prepared by a colloidal crystal template method and characterized by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray scattering elemental mapping, X-ray diffraction, Raman and X-ray photoelectron spectroscopy, and temperature-programmed reduction of H2. Further, their catalytic activity in soot combustion was determined by temperature-programmed oxidation reaction. K substitution into the LaNiO3 lattice led to remarkably improved catalytic activity of this catalyst in soot combustion. Amongst various catalysts, La0.95K0.05NiO3 exhibited the highest activity in soot combustion (with its T50 and CO2 S values being 338 °C and 98.2%, respectively), which is comparable to the catalytic activities of Pt-based catalysts under the condition of poor contact between the soot and the catalyst. K-substitution improves the valence state of Ni and increases the number of oxygen vacancies, thereby leading to increased density of surface-active oxygen species. The active oxygen species play a vital role in catalyzing the elimination of soot. The perovskite-type La1?xKxNiO3 nanocatalysts with 3DOM structure without noble metals have potential for practical applications in the catalytic combustion of diesel soot particles.

Efficient aerobic oxidative desulfurization via three-dimensional ordered macroporous tungsten-titanium oxides

A series of three-dimensional ordered macroporous(3 DOM)W-TiO_(2)catalysts have been prepared through a facile colloidal crystal template method.The prepared materials characterized in detail exhibited enhanced catalytic activity in aerobic oxidative desulfurization process.The experimental results indicated that the as-prepared materials possessed excellent 3 DOM structure,which is beneficial for the catalytic activity.The sample 3 DOM W-TiO_(2)-20 exhibited the highest activity in ODS process,and the sulfur removal can reach 98%in 6 h.Furthermore,the oxidative product was also analyzed in the reaction process.

Ordered macroporous boron phosphate crystals as metal-free catalysts for the oxidative dehydrogenation of propane

Ordered macroporous materials with rapid mass transport and enhanced active site accessibility are essential for achieving improved catalytic activity.In this study,boron phosphate crystals with a three-dimensionally interconnected ordered macroporous structure and a robust framework were fabricated and used as stable and selective catalysts in the oxidative dehydrogenation(ODH)of propane.Due to the improved mass diffusion and higher number of exposed active sites in the ordered macroporous structure,the catalyst exhibited a remarkable olefin productivity of^16 golefin gcat^-1 h^-1,which is up to 2–100 times higher than that of ODH catalysts reported to date.The selectivity for olefins was 91.5%(propene:82.5%,ethene:9.0%)at 515℃,with a propane conversion of 14.3%.At the same time,the selectivity for the unwanted deep-oxidized CO2 product remained less than 1.0%.The tri-coordinated surface boron species were identified as the active catalytic sites for the ODH of propane.This study provides a route for preparing a new type of metal-free catalyst with stable structure against oxidation and remarkable catalytic activity,which may represent a potential candidate to promote the industrialization of the ODH process.

Fabrication of ultrafine Pd nanoparticles on 3D ordered macroporous TiO_2 for enhanced catalytic activity during diesel soot combustion

Nanocatalysts consisting of three‐dimensionally ordered macroporous(3DOM)TiO2‐supported ultrafine Pd nanoparticles(Pd/3DOM‐TiO2‐GBMR)were readily fabricated by gas bubbling‐assisted membrane reduction(GBMR)method.These catalysts had a well‐defined and highly ordered macroporous nanostructure with an average pore size of 280 nm.In addition,ultrafine hemispherical Pd nanoparticles(NPs)with a mean particle size of 1.1 nm were found to be well dispersed over the surface of the 3DOM‐TiO2 support and deposited on the inner walls of the material.The nanostructure of the 3DOM‐TiO2 support ensured efficient contact between soot particles and the catalyst.The large interface area between the ultrafine Pd NPs and the TiO2 also increased the density of sites for O2 activation as a result of the strong metal(Pd)‐support(TiO2)interaction(SMSI).A Pd/3DOM‐TiO2‐GBMR catalyst with ultrafine Pd NPs(1.1 nm)exhibited higher catalytic activity during diesel soot combustion compared with that obtained from a specimen having relatively large Pd NPs(5.0 nm).The T10,T50 and T90 values obtained from the former were 295,370 and 415°C.Both the activity and nanostructure of the Pd/3DOM‐TiO2‐GBMR catalyst were stable over five replicate soot oxidation trials.These results suggest that nanocatalysts having a 3DOM structure together with ultrafine Pd NPs can decrease the amount of Pd required,and that this approach has potential practical applications in the catalytic combustion of diesel soot particles.

Synthesis of three-dimensional ordered mesoporous MnO_2 and its catalytic performance in formaldehyde oxidation

Three-dimensional（3D）ordered mesoporous MnO2 was prepared using KIT-6 mesoporous molecular sieves as a hard template.The material was used for catalytic oxidation of HCHO.The material has high surface areas and the mesoporous characteristics of the template,with cubic symmetry（ia3d）.It consists of a β-MnO2 crystalline phase corresponding to pyrolusite,with a rutile structure.Transmission electron microscopy and X-ray photoelectron spectroscopy showed that the 3D-MnO2 catalyst has a large number of exposed Mn4＋ ions on the（110）crystal plane surfaces,with a lattice spacing of 0.311 nm; this enhances oxidation of HCHO.Complete conversion of HCHO to CO2 and H2O was achieved at 130 °C on 3D-MnO2; the same conversions on α-MnO2 and β-MnO2 nanorods were obtained at 140 and 180 °C,respectively,under the same conditions.The specific mesoporous structure,high specific surface area,and large number of surface Mn4＋ ions are responsible for the catalytic activity of 3D-MnO2 in HCHO oxidation.

A novel adsorbent of three-dimensional ordered macro/mesoporous carbon for removal of malachite green dye

Three-dimensional ordered macro/mesoporous carbon(3DOM/m-C)with high specific surface area was synthesized by colloid crystal template method with chemical activation by KOH and used as the adsorbent for removing malachite green(MG)in aqueous solution.The microstructures of the adsorbents were characterized by FESEM,TEM and BET,and the effects of initial dye concentration,contact time,solution pH,and temperature on adsorption performance were investigated.The results show that the 3DOM/m-C exhibits extremely high adsorption capacity of 3541.1 mg/g within 2 h,which could be attributed to the novel ordered hierarchical structure with mesopores on three-dimensional ordered macroporous carbon walls.And the adsorption behavior conforms to the pseudo-second-order kinetic and Langmuir adsorption isotherm.3DOM/m-C can be recycled after being desorbed by absolute ethanol,and still maintains a high capacity of 2762.06 mg/g after 5 cycles.

Color tunable upconversion emission in CeO_2:Yb,Er three-dimensional ordered macroporous materials

The three-dimensional ordered macroporous CeO2：Yb,Er materials were prepared, and the influence of doping concentra- tion of Yb3＋ or Er3＋ ions on upconversion property was investigated. Green and red upconversion emissions were observed under the excitation of 980 nm at room temperature. It was found that the ratio of red to green upconversion emission intensity increased with increasing of concentration of the Yb3＋ or Er3＋ ions in the three-dimensional ordered macroporous CeO2：Yb,Er materials. When the concentration of Yb3＋ was 10 mol%, pure red upconversion emission was obtained. The varied mechanism of ratio of red to green upconversion emission intensity was discussed with the concentration of Yb3＋ or Er3＋ ions.

Superior performance in visible-light-driven hydrogen evolution reaction of three-dimensionally ordered macroporous SrTiO_(3) decorated with Zn_(x)Cd_(1−x)S

It is of broad interest to develop emerging photocatalysts with excellent light-harvesting capacity and high charge carrier separation efficiency for visible light photocatalytic hydrogen evolution reaction.However,achieving satisfying hydrogen evolution efficiency under noble metal-free conditions remains challenging.In this study,we demonstrate the fabrication of three-dimensionally ordered macroporous SrTiO_(3)decorated with Zn_(x)Cd_(1−x)S nanoparticles for hydrogen production under visible light irradiation(λ>420 nm).Synergetic enhancement of photocatalytic activity is achieved by the slow photon effect and improved separation efficiency of photogenerated charge carriers.The obtained composites could afford very high hydrogen production efficiencies up to 19.67 mmol·g^(−1)·h^(−1),with an apparent quantum efficiency of 35.9%at 420 nm,which is 4.2 and 23.9 times higher than those of pure Zn_(0.5)Cd_(0.5)S(4.67 mmol·g^(−1)·h^(−1))and CdS(0.82 mmol·g^(−1)·h^(−1)),respectively.In particular,under Pt-free conditions,an attractive hydrogen production rate(3.23 mmol·g^(−1)·h^(−1))was achieved,providing a low-cost and high-efficiency strategy to produce hydrogen from water splitting.Moreover,the composites showed excellent stability,and no obvious loss in activity was observed after five cycling tests.

Enhanced photocatalytic performance of Bi_(4)O_(5)Br_(2)with threedimensionally ordered macroporous structure for phenol removal

Herein,a series of three-dimensionally ordered macroporous(3DOM)Bi_(4)O_(5)Br_(2)photocatalysts with different macropore sizes were successfully fabricated via a polymethyl methacrylate(PMMA)template method.The photocatalytic activity for phenol degradation over 3DOM Bi_(4)O_(5)Br_(2)first increased and then decreased with the rise in macropore size.Specifically,3DOM Bi_(4)O_(5)Br_(2)-255(macropore diameter ca.170 nm)exhibits the best photocatalytic activity in the static system,which is about 4.5,7.3,and 11.9 times higher than those of bulk Bi_(4)O_(5)Br_(2),Bi_(2)WO_(6),and g-C_(3)N_(4),respectively.Meanwhile,high phenol conversion(75%)is also obtained over 3DOM Bi_(4)O_(5)Br_(2)-255 in the flow system under full spectrum irradiation.Furthermore,3DOM Bi_(4)O_(5)Br_(2)-255 also shows strong mineralization capacity owing to the downward shift of valance band position(0.15 V)as compared with Bi_(4)O_(5)Br_(2).Total organic carbon(TOC)removal rate over 3DOM Bi_(4)O_(5)Br_(2)-255(62%)is much higher than that of Bi_(4)O_(5)Br_(2)(17%).The enhancement in photocatalytic performance of 3DOM Bi_(4)O_(5)Br_(2)-255 is attributable to its better phenol adsorption,O_(2)activation,and charge separation and transfer abilities.This work combines the advantages of 3D structure and surface dangling bonds,providing new possibilities for designing highly efficient photocatalysts for pollutants removal.

Preparation of the glucose sensor based on three-dimensional ordered macroporous gold film and room temperature ionic liquid

A novel type of glucose sensor was fabricated based on a glucose oxidase(GOD)-N,N-dimethtylformamide(DMF)-[BMIm][BF4] composites modified three-dimensional ordered macroporous(3DOM) gold film electrode.The immobilized GOD exhibits a pair of well-defined reversible peaks in 50 mM pH 7.0 phosphate buffer solutions(PBS),which could be attributed to the redox of flavin adenine dinucleotide(FAD) in GOD.The research results show that ionic liquid([BMIm][BF4]),DMF and 3DOM gold film are crucial for GOD to exhibit a pair of stable and reversible peaks.It is believed that the large active area of 3DOM gold film can increase the amount of immobilized GOD.Simultaneously,the application of IL enhances the stability of GOD and facilitates the electron transfer between GOD and the electrode.The synergetic effect of DMF can help the GOD to maintain its bioactivity better.GOD immobilized on the electrode exhibits the favorable electrocatalytic property to glucose,and the prepared sensor has a linear range from 10 to 125 nM with a detection limit of 3.3 nM at a signal-to-noise ratio of 3σ.The apparent Km(Michaelis-Menten constant) for the enzymatic reaction is 0.018 mM.

有序大孔HPW/SiO_(2)催化剂制备及其对燃油深度脱硫性能研究

利用单分散聚苯乙烯微球(PS)、TEOS和HPW,制备出HPW负载量为20%(质量分数)的有序大孔HPW/SiO_(2)催化剂。该催化剂大孔规整,排列有序,孔径约340 nm,比表面积约288.1 m~2·g^(-1),并存在一定量烧结介孔,孔径平均为8 nm。在60℃、O/S为12、加入量为0.5 g条件下,该催化剂对模拟燃油中的有机硫表现出优异的催化氧化特性,2 h内对DBT脱硫转化率达99.3%,重复使用7次脱硫转化率仅下降3.9%。该催化剂对燃油中另外两种主要的有机硫BT、4,6-DMDBT的催化氧化效率分别为90.6%、84.4%。

乳化沥青对3DOM TiO_(2)雾封层材料的微观裹覆特征研究

采用三维有序大孔二氧化钛(3DOM TiO_(2))与雾封层技术相结合的方法降解路表附近的汽车尾气,可降低纳米TiO_(2)的团聚现象,提高尾气降解效果,但乳化沥青破乳后,3DOM TiO_(2)的微观裹覆特征与宏观降解性能之间的关系尚需进一步研究。因此,首先采用扫描电子显微镜(SEM)、物理吸附试验(BET)和压汞试验(MIP)测试并分析了不同孔径(200~500 nm)的3DOM TiO_(2)颗粒被乳化沥青裹覆前后的表面微观形貌、比表面积、孔径分布和孔体积。其次采用课题组自主设计的光催化性能测试分析系统测试了不同孔径的3DOM TiO_(2)雾封层材料对NO_x的降解效果,并结合孔径对3DOM TiO_(2)微观裹覆特征的影响规律,分析验证了3DOM TiO_(2)的微观裹覆特征与宏观降解性能之间的关系。研究结果表明:当孔径为300 nm时,3DOM TiO_(2)颗粒被沥青裹覆后材料中的有效孔道和比表面积最大,降解率最高。当光催化剂掺量为2%、孔径为300 nm时,3DOM TiO_(2)雾封层材料的降解率较纳米TiO_(2)雾封层材料提高了15.1%;较孔径为200、500 nm的3DOM TiO_(2)雾封层材料分别提高了5.2%、12.5%。

Synthesis of 3D ordered macroporous indium tin oxide using polymer colloidal crystal template

Three-dimensional (3D) ordered macroporous indium tin oxide (ITO) is pre- pared using a polymer colloidal crystal template that is formed by self-assembly of the monodisperse poly(methyl methacrylate) (PMMA) microspheres. The morphologies and BET surface area of the macroporous material is examined by scanning electron micro- scope, transmission electron microscopy and N2 adsorption/desorption. Results indicate that the macroporous material has highly ordered arrays of the uniform pores replicated from the PMMA colloidal crystal template when the polymer colloidal crystal template is removed by calcinations at 500℃. The pore diameter (about 450 nm) of macroporous ITO slightly shrank to the PMMA microspheres. The BET surface area and pore volume of the macroporous material are 389 m2·g-1 and 0.36 cm3·g-1, respectively. Moreover, the macroporous ITO, containing 5 mol% Sn and after annealing under vacuum, shows the minimum resistivity of ρ = 8.2×10-3 Ω· cm. The conductive mechanism of macroporous ITO is discussed, and it is believed that the oxygen vacancies are the major factor for excellent electrical properties.

Synthesis of 3-D ordered macroporous silicate using the template formed from monodispersed polystyrene latex

Based on the template formed from monodispersed polystyrene (PS) latex, a modified fast sol-gel process was employed to synthesize a three-dimensional ( 3-D ) ordered macroporous silica material after removing the template by calcination at high temperature. It was indicated that there existed highly ordered packed pores within the whole silica material by SEM morphology observation. It was also found that the pores were interconnected. The pore size could be controlled mainly by varying the particle size of the latex ranging from 101 to 102 nm. The formation process of the ordered pores was also preliminarily discussed.