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Conversion of synthesis gas to gaseous and liquid fuels via Fischer-Tropsch (FT) synthesis is becoming increasingly important for future energy needs. Tube-wall reactors (TWR) are gaining importance for l T synthesis because of simple construction and improved temperature control. In the literature, studies have been reported on the fl synthesis in a TWR using a flame-sprayed iron catalyst. In the present work, we have examined the effect of temperature (250-275°C). pressure (3.45 X 10' -6.89 X 10' Pa), exposure velocity (0.61 -2.44 m3/h of gas at STP/m2 of catalyst superficial area) and feed composition (H2/C0 ratio of 2 and 3) on the product yield and selectivity using a plasma-sprayed iron catalyst in the TWR. The plasma-sprayed iron catalyst gave slightly lower conversions but showed much higher Cs+ product selectivity as compared to the flame-sprayed catalyst. The product distribution shifted towards higher hydrocarbons at lower temperatures. higher pressures and lower exposure velocities. The product distribution followed Shultz-Flory relationship and the chain growth probability factor a decreased slightly with increase in temperature. The catalyst also showed good regeneration characteristics.La conversion du gaz de synthtse en combustibles liquides et gazeux par la synthkse Fischer-Tropsch (FT) rev& une

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The efficient reduction of CO2 into valuable products such as methanol, over metal-organic frameworks (MOFs) based catalyst, has received much attention. The photocatalytic reduction is considered the most economical method due to the utilization of solar energy. In this study, Copper (II)/Zeolitic Imidazolate Framework-8 (Cu/ZIF-8) catalysts were synthesized via a hydrothermal method for photocatalytic reduction of CO2 to methanol. The synthesized catalysts were characterized by X-ray Photoelectron Spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FESEM) coupled with Energy Dispersive X-ray (EDX), Ultraviolet-visible (UV-vis) spectroscopy, and X-Ray Diffraction (XRD). The host ZIF-8, treated with 2 mmol copper prepared in 2M ammonium hydroxide solution showed the highest photocatalytic activity. The crystal structures of ZIF-8 and 2Cu/ZIF-8N2 catalysts were observed as cubic and orthorhombic, respectively and the XPS analysis confirmed the deposition of Cu (II) ions over ZIF-8 surface among all the prepared catalysts. The orthorhombic structure, nano-sized crystals, morphology and Cu loading of the 2Cu/ZIF-8N2 catalyst were the core factors to influence the photocatalytic activity. The yield of Methanol was found to be 35.82 µmol/L·g after 6 h of irradiations on 2Cu/ZIF-8N2 catalyst in the wavelength range between 530–580 nm. The copper-based ZIF-8 catalyst has proven as an alternative approach for the economical photocatalytic reduction of CO2 to CH3OH.

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