Title : Direct activation of CH4to oxygenates and unsaturated hydrocarbonsusing N2O on Fe-modified zeolites
Authors : Kyung Soo Park, Jeong Hwa Kim, So Hyun Park, Dong Ju Moon, Hyun-Seog Roh,Chan-Hwa Chung, Soong Ho Um, Joon-Hwan Choi, Jong Wook Bae

Journal : Journal of Molecular Catalysis A: Chemical
Vol/No/Page : 426/130-140
DOI : http://dx.doi.org/10.1016/j.molcata.2016.11.008

Abstract :
 Direct activation of CH4to oxygenates and unsaturated light hydrocarbons was investigated using Fe-modified ZSM-5 and Ferrierite (FER) for a partial oxidation of CH4with N2O oxidant. The amount ofactive  -oxygen sites and number of Bronsted acid sites on the Fe-modified zeolites were well correlatedwith CH4conversion rate and product distributions. The amount of  -oxygen sites was largely changedaccording to preparation method such as wet impregnation or ion-exchange of iron precursor and typesof zeolites. A large number of Bronsted acid sites and  -oxygen sites on the Fe-modified FER revealed ahigher oxygenate formation such as methanol and dimethyl ether (DME) with COx, and a larger number ofstrong acid sites on Fe-modified ZSM-5 was also responsible for a higher selectivity to light hydrocarbonsby a successive dehydration of oxygenates formed. The different catalytic performances were verifiedthrough proper measurements of the amount and type of acidic sites as well as the  -oxygen sitesmeasured by N2O pulse chemisorption. The Fe-modified FER prepared by impregnation method possesseda larger amount of  -oxygen sites due to abundant Bronsted acid sites, which was responsible for a higherrate of CH4conversion to oxygenates with the help of N2O decomposition on the  -oxygen sites originatedfrom iron oxide nanoparticles.