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The impregnation and ion exchange methods were employed to prepare the Ni-modified clinoptilolites (CPs). Their physicochemical properties and structural features were evaluated by various characterizations, such as XRD patterns, SEM and TEM images, Raman and FT-IR spectra, XPS and H 2 -TPR, N 2 sorption isotherms, and TG analysis. The results demonstrated that the loaded Ni nanoparticles were highly dispersed on the lamellar surfaces of the synthesized CPs. Meanwhile, their CH 4 and CO 2 dry reforming reactions (DRM) at 500–900 °C were conducted utilizing Ni species as active sites. The results demonstrated that the Ni-loaded CPs exhibited greater catalytic activity than the Ni-exchanged CPs, besides that, the Ni-loaded CPs demonstrated the highest catalytic stability at 700 °C. However, the carbon deposition of the Ni-loaded CPs seemed more difficult to eliminate than that of the Ni-exchanged CPs in the DRM durations. These results elucidate the excellent performances of the developed Ni-modified CPs for designing more stable and efficient Ni-based DRM catalysts. [Display omitted] • Ni-modified clinoptilolite (CP) was synthesized for CH4-CO2 reforming reaction. • DRM catalytic activity of Ni-loaded CP is higher than that of Ni-exchanged CP. • Ni-loaded CP showed an excellent DRM catalytic activity. • The well-dispersed Ni-nanoparticle was distributed in lamellar surface of CP. • Limitation of diffusion and adsorption of reactant and intermediate was overcome. [ABSTRACT FROM AUTHOR]

The large amount of carbon dioxide (CO2) emissions has seriously threatened the living environment of human beings. Electrocatalytic conversion of CO2 is one of the most promising methods as it can not only reduce the hazards associated with excessive emissions but also obtain fuels or other chemicals. Current research has found that the changes in the performance of catalysts are caused by the external environment, but their mechanisms affecting CO2 reduction are still not clear enough. Herein, based on density functional theory (DFT) calculations, ions X (X = Cl−, Na+ and S2−) were introduced to change the atomic environment of metalloporphyrins (MPPs). The effects of the atomic environment of the active site on CO2 catalytic performance were systematically investigated. Our results show that the doping of ions regulates the metal electronic state, which can change the CO2 catalytic activity and selectivity on MPPs. Deeply understanding the CO2 reduction mechanism provides a theoretical fundament for designing high-performance and high-selectivity CO2 electrochemical reduction schemes. [ABSTRACT FROM AUTHOR]

A novel nanocatalyst design using nanomaterials through active-zone crystallisation was proposed. The hydrothermal crystallisation of amorphous dendritic fibrous nano-titanium dioxide with Ni (DFNT/Ni) sites was determined to be the main step in producing extremely active dendritic DFNT/Ni zones, which in turn dramatically enhanced their catalytic activities. DFNT/Ni was then combined with polyvinyl alcohol (PVA) by using a traditional individual-nozzle electrospinning method, and the resulting material was named PVA-DFNT/Ni. This method was utilised to produce 3-aryl-2-oxazolidinones from ethylene oxide, CO2, and anilines. The prepared catalytic apparatus was eco-friendly and had the advantages of high catalytic activity, ability to improve the reaction mixture, and reusability without a considerable decrease in efficiency. It is extracted in the straight and adoptive chemical fixation of flue-gas CO2 obtained from industrial emissions, thereby achieving high degrees of CO2 absorption and conversion. [ABSTRACT FROM AUTHOR]

Toluene, dichloromethane, and methanethiol were selected as probe molecules for aromatic, chlorinated, and sulfurated VOCs, respectively, to evaluate the catalytic properties of Pt/CeO 2 composites. The T 90 for toluene, DCM, and methanethiol oxidation were only 153, 265, and 240 °C, when 0.9 wt% Pt/CeO 2 was used as the catalyst. The synergy between Pt and support could be responsible for the high catalytic activity and antipoisoning properties. When combined with NDIR CO 2 sensors, the composite could be used for atmospheric total organic carbon detection. The recorded data almost overlap with that of the theoretical, suggesting the excellent reliability of the dictation system. The Pt/CeO 2 composite with abundant oxygen vacancies could use as a catalyst not only for VOCs elimination but also for atmospheric total organic carbon detection when combined with NDIR CO 2 sensors. [Display omitted] • The composites possess highly dispersed Pt species and abundant oxygen vacancies. • The 0.90% Pt/CeO 2 has the highest catalytic activities and excellent anti-poisoning properties. • The composite also could be used as catalyst for atmospheric total organic carbon detection. [ABSTRACT FROM AUTHOR]

• The different patterns of total resistance with current for different mixture were emphasized. • The causes for the different total resistance patterns were explored. • The electrode catalytic activity influenced significantly the activation resistance pattern. • The mechanism of co-electrolysis was explored based on the resistance patterns. • The contribution of electrochemical reduction of CO 2 to the production of CO was experimentally clarified. The reaction mechanism of co-electrolysis on the solid oxide electrolysis cells (SOEC) was widely discussed and no consensus had ever been reached. The performance of CO 2 electrolysis, H 2 O electrolysis and co-electrolysis was tested on an industrial-size cell with a conventional structure of Ni-YSZ|YSZ|GDC|LSCF. The co-electrolysis performance was inferior to that of H 2 O electrolysis but superior to that of CO 2 electrolysis. Also, the total resistance (R tot) of co-electrolysis first increased to a maximum and then began to descend with the increase of applied current, which was similar to the R tot pattern of CO 2 electrolysis but totally different from the monotonous increasing R tot pattern of H 2 O electrolysis. Study on a button cell with the same structure as the industrial-size cell showed that the catalytic activity of fuel electrode for H 2 O electrolysis was 9 times higher than that for CO 2 electrolysis and this huge difference might be the main cause of the different activation resistance (R act) and thus different R tot behavior of H 2 O electrolysis and CO 2 electrolysis. The appearance of R tot summit can be regarded as the signal of dominance of CO 2 electrochemical reduction during co-electrolysis. Based on the position of R tot summit and the impedance spectroscopy (EIS) results, the reaction mechanism of co-electrolysis was explored and it was found H 2 O electrolysis dominated at small current density and CO 2 electrolysis gradually occurred and dominated with the increase of current density. Besides, H 2 concentration in the inlet showed a more profound impact on the reaction mechanism of co-electrolysis compared to CO 2 concentration. [ABSTRACT FROM AUTHOR]

Rationally designed bio-AILs show exceptional performance for CO 2 activation and conversion into quinazoline-2,4(1 H ,3 H)-diones under mild conditions. [Display omitted] • Novel biocompatible media are developed for CO 2 /2-aminobenzonitrile reaction. • The bio-AILs media are facilely synthesized, highly stable and inexpensive. • The present media realizes the simultaneous activations of CO 2 and substrate. • The [HTMG][Lae] shows superior activity under mild and additive-free conditions. • The [HTMG][Lae] as dual solvent-catalyst is recyclable with excellent reusability. Based on an one-step acid-base neutralization method, several biocompatible anions-derived ionic liquids (bio-AILs) were prepared and characterized. They were first used as dual solvent-catalyst for cyclization of CO 2 and 2-aminobenzonitriles to synthesize quinazoline-2,4(1 H ,3 H)-diones. The influence of different bio-AILs structures on the cyclization reaction were studied, and [HTMG][Lae] was confirmed to be an excellent medium. By optimizing the reaction conditions, the [HTMG][Lae]-mediated cyclization reaction could afford a 96 % quinazoline-2,4(1 H ,3 H)-dione yield at 70 °C, 1.0 MPa CO 2 pressure for 6 h without other additives. The catalytic activities of various homogeneous media for transformation of CO 2 into quinazoline-2,4(1 H ,3 H)-dione were analyzed and compared. In addition, the reusability and general applicability of the [HTMG][Lae] medium were examined, the [HTMG][Lae] could show comparable activity in the fifth experiment, and it had good versatility for cyclization of CO 2 with various 2-aminobenzonitriles. Finally, an insight into the activation behaviors of [HTMG][Lae] to reactants were further investigated, and based on this, a feasible reaction mechanism was proposed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mesoporous MCo2O4(4.5) has been successfully fabricated using a facial one-pot pyrolytic protocol. [•] Material MnCo2O4.5 calcined at 250°C at a heating rate of 1°C/min possessed high surface area. [•] It possesses excellent catalytic activity for CO oxidation at low temperature. [ABSTRACT FROM AUTHOR]

Self-assembled catalyst has the excellent selectivity and activity at low concentrations of CO 2. [Display omitted] • The self-assembled catalyst of CC3/Pd is synthesized. • Catalyst has the excellent selectivity and activity at low concentrations of CO 2. • The size effect of Pd nanoparticles has been systematically studied. • The mechanism of catalyst photoreduction CO 2 to CH 4 is studied. Porous heterogeneous photocatalysts containing both CO 2 adsorption and catalytically active sites can be might beneficial to achieve photoreduction of low concentrations of CO 2 to methane. Here, we show a self-assembled catalyst by combining catalytically-active Pd nanoparticles and porous organic cages for the CO 2 -to-CH 4 photoreduction reaction in the presence a molecular photosensitizer and a sacrificial reagent. The Pd nanoparticles is vital for the high CH 4 selectivity (over 97%) for the CO 2 photoreduction reaction, but they suffer from the low catalytic activity. When these Pd nanoparticles are equipped with an underneath support of porous organic cages, it dramatically boosts the catalytic activity with a high production rate of 78.5 μmol g-1h−1, while the CH 4 selectivity is up to ∼ 98% (electron basis). Importantly, when the photoreduction is performed under low concentration of CO 2 (10% concentration), over 98% of CH 4 selectivity and nearly 50% of the catalytic activity for the Pd-based catalysts retains. [ABSTRACT FROM AUTHOR]

Task-specific Py-Zn@IPOP X with multiple active sites are developed and exhibit durable high-activity for cycloaddition of CO 2 to epoxides under additive-free conditions. [Display omitted] • Novel task-specific Py-Zn@IPOP X are constructed in green ionic liquid medium. • Py-Zn@IPOP I with multiple active sites can activate CO 2 and epoxide simultaneously. • Py-Zn@IPOP I realizes efficient CO 2 cycloaddition under additive-free conditions. • The developed catalyst is easily separated and exhibits durable high-activity. Based on the Schiff base reaction and post-modification strategy, novel nanocomposites of pyridine-zinc-based ionic porous organic polymers (Py-Zn@IPOP X , X = Br, I, Ac) were constructed and structurally characterized. Various Py-Zn@IPOP X were applied to the transformation of CO 2 and epoxides into cyclic carbonates, and their catalytic activities were studied and discussed in detail. The results showed that Py-Zn@IPOP I possesses Lewis acid-base bifunctional features, and also modified with superior nucleophilic active groups, which exerted an important synergistic effect on activation of CO 2 and epoxide, and ring-opening of epoxide. Under co-catalyst/solvent-free conditions, Py-Zn@IPOP I could afford 96 % PC yield and 99 % selectivity at 120 °C and 2.0 MPa CO 2 pressure for 6 h, and turnover frequency (TOF) was high to 230 h−1. Moreover, the reusability and versatility of the catalyst were examined, and the catalytic mechanism was speculated according to the obtained results. Compared with previously reported porous polymer catalysts, Py-Zn@IPOP I requires much greener and milder reaction conditions while avoids the use of a co-catalyst, displaying bright prospects for the design and synthesis of ionic porous organic polymers for CO 2 activation and utilization. [ABSTRACT FROM AUTHOR]

Heterogeneous Co@PTPOFs with multiple Lewis acid/basic sites are developed and show excellent activity for cycloaddition of CO 2 and epoxides. [Display omitted] • Novel M@PPOFs with multiple Lewis acid/basic active sites are prepared facilely. • The M@PPOFs exhibit high specific surface area and good structural stability. • The 1.0Co@PPOFs-mediated CO 2 coupling reaction can conduct under mild conditions. • The optimum catalyst shows excellent reusability and broad substrate scope. • An insight into the M@PPOFs-catalyzed cycloaddition mechanism is proposed. A series of metal-decorated porous organic frameworks (M@PTPOFs) with cross-linked pyridyl and triazinyl were fabricated through a two-step method. The structures of the PTPOFs and M@PTPOFs were systematically characterized. As heterogeneous catalysts with Lewis acid/basic sites, the M@PTPOFs were applied to catalyze the model cycloaddition of CO 2 and epoxides. The optimal catalytic system and reaction parameters were investigated in detail. It was found that 1.0Co@PTPOF-400-15 cooperating with tetrabutylammonium iodide (TBAI) achieved the best catalytic performance, with a 96% product yield and 99% selectivity under mild conditions of 60 °C and 2.0 MPa CO 2 for 5.0 h. Moreover, 1.0Co@PTPOF-400-15 could be easily recycled by centrifugation and reused multiple times with nearly unchanged catalytic activity. Finally, the product yield and reaction parameters were compared with those of reported heterogeneous catalysts, and the possible synergistic catalytic mechanism of 1.0Co@PTPOF-400–15/TBAI was proposed. The multiple Lewis acid/basic active sites, robust structure and excellent catalytic performance are useful for the development of other high-efficiency heterogeneous catalysts. [ABSTRACT FROM AUTHOR]