27Al spin-echo, high-speed MAS (nu(rot) = 30 kHz), and MQMAS NMR spectroscopy in magnetic fields of B0 = 9.4, 14.1, and 17.6 T were applied for the study of aluminum species at framework and extra-framework positions in non-hydrated zeolites Y. Non-hydrated gamma-Al2O3 and non-hydrated aluminum-exchanged zeolite Y (Al,Na-Y) and zeolite H,Na-Y were utilized as reference materials. The solid-state 27Al NMR spectra of steamed zeolite deH,Na-Y/81.5 were found to consist of four signals. The broad low-field signal is caused by a superposition of the signals of framework aluminum atoms in the vicinity of bridging hydroxyl protons and framework aluminum atoms compensated in their negative charge by aluminum cations (delta(iso) = 70 +/- 10 ppm, C(QCC) = 15.0 +/- 1.0 MHz). The second signal is due to a superposition of the signals of framework aluminum atoms compensated by sodium cations and tetrahedrally coordinated aluminum atoms in neutral extra-framework aluminum oxide clusters (delta(iso) = 65 +/- 5 ppm, C(QCC) = 8.0 +/- 0.5 MHz). The residual two signals were attributed to aluminum cations (delta(iso) = 35 +/- 5 ppm, C(QCC) = 7.5 +/- 0.5 MHz) and octahedrally coordinated aluminum atoms in neutral extra-framework aluminum oxide clusters (delta(iso) = 10 +/- 5 ppm, C(QCC) = 5.0 +/- 0.5 MHz). By chemical analysis and evaluating the relative solid-state 27Al NMR intensities of the different signals of aluminum species occurring in zeolite deH,Na-Y/81.5 in the non-hydrated state, the aluminum distribution in this material was determined.

New graphene oxide (GO)-tethered-Co(II) phthalocyanine complex [CoPc-GO] was synthesized by a stepwise procedure and demonstrated to be an efficient, cost-effective and recyclable photocatalyst for the reduction of carbon dioxide to produce methanol as the main product. The developed GO-immobilized CoPc was characterized by X-ray diffraction (XRD), FTIR, XPS, Raman, diffusion reflection UV/Vis spectroscopy, inductively coupled plasma atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). FTIR, XPS, Raman, UV/Vis and ICP-AES along with elemental analysis data showed that Co(II) -Pc complex was successfully grafted on GO. The prepared catalyst was used for the photocatalytic reduction of carbon dioxide by using water as a solvent and triethylamine as the sacrificial donor. Methanol was obtained as the major reaction product along with the formation of minor amount of CO (0.82 %). It was found that GO-grafted CoPc exhibited higher photocatalytic activity than homogeneous CoPc, as well as GO, and showed good recoverability without significant leaching during the reaction. Quantitative determination of methanol was done by GC flame-ionization detector (FID), and verification of product was done by NMR spectroscopy. The yield of methanol after 48 h of reaction by using GO-CoPc catalyst in the presence of sacrificial donor triethylamine was found to be 3781.8881 μmol g(-1)  cat., and the conversion rate was found to be 78.7893 μmol g(-1) cat. h(-1). After the photoreduction experiment, the catalyst was easily recovered by filtration and reused for the subsequent recycling experiment without significant change in the catalytic efficiency.

It is generally accepted that free carbenium cations mostly exist as transition states rather than as long-lived intermediates in acid-catalyzed reactions performed on acidic zeolites.[1] Surface alkoxy species with carbenium-like properties are suggested to be, most likely, the catalytic intermediates in zeolite chemistry. [2][3][4][5] However, these surface alkoxy species on acidic zeolite catalysts are not easy to detect [5][6][7] by solid-state NMR spectroscopy, which hinders further elucidation of their catalytic role in heterogeneous catalysis. For example, the 13 C NMR observation of simple surface ethoxy species has never been reported on acidic zeolites, [8] although it has been predicted [1c] that the stability of surface alkoxy species on acidic zeolites follows the order of ethoxy > propoxy > tert-butoxy. The difficulties in observing surface alkoxy species on acidic zeolites by NMR spectroscopy may lie in two aspects: In the case of olefin adsorption on acidic zeolites, fast oligomerization of olefins [7, 8] takes place even at ambient temperature in comparison with the slow detection by NMR spectroscopy. In the case of alcohol adsorption on acidic zeolites, on the other hand, removal of water is necessary [5,6, 9] because water will readily quench-off surface alkoxy species to the corresponding alcohols. However, most solid-state NMR investigations were performed under batch conditions with samples in fused glass ampoules or in gas-tight rotors, where further evacuation in vacuum at proper temperatures can hardly be achieved to remove water and to prevent the further reaction of surface alkoxy species.Herein, the first solid-state 13 C magic-angle spinning (MAS) NMR evidence for the existence of surface ethoxy species on acidic zeolite Y by applying a stopped-flow protocol [5] is presented. Moreover, the further decomposition of surface ethoxy species to hydrocarbons and carbenium cations at elevated reaction temperatures was studied by the new developed [10]

Visible light assisted copper catalyzed surface initiated atom radical transfer polymerization system for polymer growth from titania/reduced graphene oxide (TiO2/rGO) has been described.

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