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A novel rod-shaped MIL-88A(Fe)@CuS featured with sulfur vacancies (S V) were constructed as heterogeneous catalysts for activating peroxymonosulfate (PMS) for coumarin (COU) degradation. A series of x MIL@CuS were obtained according to the mass content of MIL-88A(Fe) in the composites (x , wt% = 50 %, 65 %, and 80 %). Among them, 65 % MIL@CuS hold the best performance, and realized a complete COU removal (30 μM) in 7 min (0.2 g/L 65 %MIL@CuS and 0.5 mM PMS). The degradation was much more favorable in acidic initial pH than alkaline initial pH. The calculated reaction rate constants at initial pH of 3.0, 5.0, 6.0 and 9.0 were 0.903, 0.729, 0.650 and 0.095 min−1, respectively. Electron paramagnetic resonance (EPR) analysis, radical scavenging tests and mechanism exploration indicated that the main difference in degradation under acidic and alkaline pH came from the yield of 1O 2. In initial pH = 3.0 condition, S V and lattice oxygen on 65 %MIL@CuS participated in the generation of 1O 2 , greatly increasing the content of 1O 2 (11.6 × 10−11 M) and promoting the degradation. While under initial alkaline condition (pH = 9.0), 1O 2 were basically produced from the reaction between Cu(II) and PMS, resulting in a low yield (1.7 × 10−11 M) and lower degradation. Besides, 65 %MIL@CuS maintained excellent reusability with low metal ions leaching, and the degradation exceeded 98.0 % even in the fifth run. Overall, this work provided an efficient and stable activator for activating PMS to degrade refractory organics, and managed to disclose the activation mechanisms under acidic and alkaline pH. [Display omitted] [ABSTRACT FROM AUTHOR]

For understanding the relationship between the structure and catalytic property and further optimizing the synthetic steps, it is imperative to obtain basic information about the characteristics of heterogeneous catalysts, such as porosity, dispersion, and accessibility of the active metal phases. Herein, we reported a multiscale analysis of an eggshell-Co-based catalyst for the Fischer-Tropsch synthesis (FTS), which was prepared by wetness impregnation. Conventional characterization techniques, such as mercury porosimetry, nitrogen physisorption, and transmission electron microscopy (TEM), were employed for obtaining basic information about the porosity and dispersion of cobalt on the nanoscale; in addition, phase-contrast X-ray computed microtomography (X-ray μCT) as a powerful method was employed for obtaining vitally complementary information regarding the 3 D structure of a millimeter-sized mesoporous silica support and a full-field view of the macroscopic distribution of cobalt. The Co reduction behavior and FTS performance was correlated with the structure analyses, highlighting the importance of simultaneously controlling the dispersion and spatial distribution of Co ranging from macro to nanoscale. [ABSTRACT FROM AUTHOR]

• CZTS nanoparticles synthesized with solvents of deionized water and ethylene glycol were utilized in catalytic H 2 O 2 process. • CZTS-W exhibited higher recyclability and stability than CZTS-EG. • 1O 2 played the dominant role in SDZ degradation. • The catalytic mechanisms of CZTS-W/H 2 O 2 and CZTS-EG/H 2 O 2 systems were proposed. • The synergetic effect of Cu2+/Cu+ and low-valent sulfur/high-valent sulfur was in favor of H 2 O 2 activation. As a quaternary copper-based semiconductor, Cu 2 ZnSnS 4 (CZTS) is drawing growing attention and is anticipated as a promising photocatalyst, thanks to its large absorption coefficient, exceptional photostability, and theoretical power conversion efficiency. However, CZTS has never been used as an activator of H 2 O 2 for the degradation of refractory organic pollutants. In this study, the synthesis of CZTS nanoparticles obtained with diverse morphologies and crystallinities using solvents of deionized water (CZTS-W) and ethylene glycol (CZTS-EG) was examined in the activation of H 2 O 2 to degrade sulfadiazine (SDZ). The results revealed that CZTS coupled with H 2 O 2 could be an effective system for the degradation of SDZ. Compared to CZTS-EG, CZTS-W presented higher reusability in consecutive cycles with negligible leaching of copper. Reactive oxygen species quenching tests and electron paramagnetic resonance analyses illustrated that •O 2 −, •OH, and 1O 2 contributed to the degradation of SDZ, and 1O 2 prevailed over •O 2 − and •OH. The mechanistic investigation showed that efficient degradation could be associated to the effective recycling of Cu(II)/Cu(I) and low-valent/high-valent sulfur. Also, the degradation pathways of SDZ have been proposed through the detection of intermediate products. This study manifests that CZTS synthesized using deionized water is encouraging for the elimination of organic pollutants. [ABSTRACT FROM AUTHOR]

The Front Cover shows a 3D view of the spatial distribution of active metal phases in a millimeter‐sized porous support. In their Full Paper, T. Han, X. Li et al. employed phase‐contrast X‐ray computed microtomography (X‐ray μCT) to image the 3D structure of the cobalt eggshell catalyst. Based on the critical structure information from X‐ray μCT and other conventional characterization technologies, the Fischer–Tropsch performance of eggshell catalysts was fully understood. Their results provide new insights into the impregnation behavior on the millimeter‐sized porous support and offer novel perspectives toward the rational design of industrial catalysts. More information can be found in the Full Paper by T. Han, X. Li et al. on page 2920 in Issue 18, 2016 (DOI: 10.1002/cctc.201600657). [ABSTRACT FROM AUTHOR]

• Oxygen vacancies enriched CoAl-LDH@CoS x hollow flowers was synthesized. • CoAl-LDH@CoS x exhibited excellent catalytic activity for sulfamethoxazole degradation. • 1O 2 was identified as the primary reactive species in the oxidation process. In this study, oxygen vacancies enriched cobalt aluminum hydroxide@hydroxysulfide (CoAl-LDH@CoS x) hollow flowers was synthesized by in-situ etching of CoAl-LDH using sodium sulfide solution. The analysis of SEM, EDS, XRD, and XPS were used to characterize the samples. The as-synthesized 0.2CoAl-LDH@CoS x displayed higher catalysis performance of sulfamethoxazole (SMX) degradation via the activation of PMS than the pristine CoAl-LDH. 98.5 % of SMX (40 μM) was eliminated with 0.1 g/L 0.2CoAl-LDH@CoS x and 0.3 mM PMS at pH 6.0 in 4 min. The degradation fitted with the pseudo-first-order reaction kinetics well with rate constant of 0.89 min−1 for 0.2CoAl-LDH@CoS x /PMS system and 0.55 min−1 for CoAl-LDH/PMS system. Singlet oxygen (1O 2) was verified as dominant reactive oxygen species responsible for SMX degradation via quenching tests. Mechanism investigation suggested that the oxygen vacancies, redox cycles of Co(II)/Co(III) and S 2 2−/(S2− and sulfate species) on the surface of 0.2CoAl-LDH@CoS x were crucial for PMS activation. In addition, the plausible degradation pathways of SMX were proposed by analysis of the SMX degradation intermediates. This study not only reveals that 0.2CoAl-LDH@CoS x is an efficient catalyst to activate PMS for SMX degradation, but also shed a novel insight into development of heterogeneous catalysts with oxygen vacancies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sulfur vacancies-enriched CuS@MIL-101(Fe) sphere was fabricated. • CuS@MIL-101(Fe) realized a rate constant of 0.577 min−1, which was 11.1 and 17.0 times of CuS and MIL-101(Fe), respectively. • CuS@MIL-101(Fe) exhibited satisfactory stability and recyclability for COU degradation. • •OH and 1O 2 were identified as the predominant ROS. For improving the catalytic activity and recyclability of CuS in Fenton-like reaction processes, novel sulfur vacancies-enriched CuS@MIL-101(Fe) was constructed, characterized, and examined as heterogeneous catalysts for activating peroxymonosulfate (PMS) to degrade coumarin (COU). Thanks to the redox pairs of Fe3+/Fe2+, Cu+/Cu2+, S2−/S 2 2−/S0/sulfate species, copper-iron synergistic effect and sulfur vacancies, the CuS@MIL-101(Fe) realized a complete removal of COU (30 μM) in 10 min with reaction rate constant of 0.577 min−1, which was 11.1 and 17.0 times of CuS and MIL-101(Fe), respectively. The effect of various experimental conditions (i.e., initial pH, CuS@MIL-101(Fe) dosage, PMS concentration, and background anions) on COU degradation was discussed, and the stability and versatility of CuS@MIL-101(Fe) was studied as well. Radical scavenging experiments and electron paramagnetic resonance (EPR) spectroscopy identified •OH and 1O 2 as the main reactive oxygen species (ROS). Finally, the possible mechanism of higher COU degradation efficiency in the CuS@MIL-101(Fe) activated PMS system and the degradation pathways were also deeply explored. Consequently, this work provided a novel insight into construction of sulfur vacancies-enriched heterogeneous catalysts for efficiently activating PMS for refractory organic pollutants elimination. [ABSTRACT FROM AUTHOR]

[Display omitted] • Prussian blue analogues@MXene composite (PBA@MXene) was fabricated. • PBA@MXene exhibited excellent catalytic activity for coumarin degradation. • Alkaline condition was more favorable for coumarin degradation. • Lewis-acid sites on MXene was crucial for PMS activation. In this study, with two dimensional MXene as the substrate, Prussian blue analogues@MXene composite (PBA@MXene) was fabricated and utilized as a heterogeneous catalyst for the oxidative degradation of coumarin (COU) based on peroxymonosulfate activation. The initial pH strongly affected the degradation process, and the alkaline pH was beneficial to the COU degradation than the acidic pH. The kinetic rate constants were determined to be 0.030, 0.055, 0.121 and 0.246 min-1at pHs of 3.0, 5.0, 6.6 and 10.0, respectively. The TOC removal efficiency achieved at pH 10.0 was 70.9% in 20 min reaction time. Radical scavengers tests showed that in the presence of 500 mM tert-butyl alcohol (TBA), the rate constant was gradually enhanced from 0.004 to 0.040 min−1 with increasing the solution pH from 3.0 to 10.0; while with the addition of 500 mM Methanol (Me), the rate constants were determined to be 0.002, 0.001, 0.002, and 0.002 min−1 at pHs of 3.0, 5.0, 6.6, and 10.0, respectively. Mechanism study indicated that the differences in COU degradation at different pHs could be mainly ascribed to the unsaturated Ti-C-O (Lewis-acid site) and terminal F-Ti on the catalyst surface. This work not only demonstrated that 1.2PBA@MXene was a promisingly effective catalyst for PMS activation for COU degradation, but also clearly spelled out the role of Lewis-acid sites of MXene in MXene-based catalysts. [ABSTRACT FROM AUTHOR]