Steam pre-reforming of natural gas over nanostructured Ni/12CaO-7Al(2)O(3) catalyst for hydrogen production: effect of support preparation method

作者：Keshavarz Ahmad Reza; Soleimani Mansooreh

来源：Research on Chemical Intermediates, 2018, 44(3): 1485-1503.

DOI：10.1007/s11164-017-3180-4

• Pre-reforming of natural gas
• Calcium aluminate
• Ni-based catalysts
• Syngas

Calcium aluminate (12CaO-7Al(2)O(3)) powder was synthesized using three methods, viz. Pechini, coprecipitation, and a new novel facile decomposition route starting from activated alumina and calcium nitrate precursors, then used as a support to prepare a series of 31 wt%Ni/12CaO-7Al(2)O(3) catalysts by deposition-precipitation method. The resultant catalysts were tested in steam pre-reforming of natural gas at 400-550 A degrees C, low steam-to-carbon (S/C) molar ratio of 1.5, and atmospheric pressure. The obtained samples were characterized by Brunauer-Emmett-Teller (BET) analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), hydrogen chemisorption, and CO2-temperature-programmed desorption (TPD). Experimental results showed that the basicity and morphology of the supports depended significantly on the synthesis method. Calcium aluminate synthesized using the new decomposition procedure showed surface area of 6.23 m(2) g(-1), while the surface area of those prepared by the Pechini and coprecipitation method were 1.38 and 3.76 m(2) g(-1), respectively. The catalytic properties of the 31 wt%Ni/12CaO-7Al(2)O(3) catalysts were strongly influenced by the support preparation approach. The highest specific surface area (about 230 m(2) g(-1)), smallest Ni particle size (8.86 nm), and highest nickel dispersion (7.48%) were observed for the catalyst whose support was synthesized by the decomposition method. Even at high gas hourly space velocity (GHSV) of 2 x 10(5) mL h(-1), this catalyst exhibited around 100% C2H6 and C3H8 conversion at temperature above 500 A degrees C. High catalytic stability during 60 h time on-stream was also shown. The TPO profiles of the spent catalyst demonstrated high resistance to carbon formation.

• 出版日期2018-3