Catalytic performance and kinetic modeling of ethylene glycol steam reforming over surfactant-modified Pd–Ni/KIT-6

Abstract

In the current study, steam reforming of ethylene glycol as a well-known bio-oxygenate, was carried out over 2%Pd–10%Ni/KIT-6 catalyst in a fixed-bed reactor. 2%Pd–10%Ni/KIT-6 was synthesized via surfactant-assisted impregnation method, whose physicochemical properties were determined by XRD, XRF, BET, FE-SEM, EDX-dot mapping, TEM, H 2 -TPR, NH 3 -TPD and TGA analyses. The performance of the synthesized catalyst was investigated at temperatures from 623 to 773 K and at 10 wt% of ethylene glycol in water. Furthermore, the W cat /F EG0 ratio varied between 100.08 and 202.22 (g h mol −1 ). At T = 773 K and W cat /F EG0 = 202.22, ethylene glycol conversion and H 2 yield were 99.8% and 71.36%, respectively. Also, a stability test of 2%Pd–10%Ni/KIT-6 was conducted for 28 h. No significant change was shown in the catalytic activity. Some different models were used to describe the kinetic behavior. The power-law model indicated that the reaction order changed with temperature. The kinetic data were interpreted by the Langmuir-Hinshelwood models, in which the surface reaction between the adsorbed reactants was considered as a rate-determining step. The activation energy for the Langmuir-Hinshelwood and power-law models were 28.03 and 33.07 kJ mol −1 , respectively. This synthesized nanocatalyst as the first Pd–Ni/zeolite in SREG through well-known kinetics and mechanism, is superior in high stability, excellent EG conversion, good yield and selectivity to H 2 and less production of toxic products. • 2%Pd–10%Ni/KIT-6 was prepared by surfactant-assisted-impregnation method. • EG steam reforming over Pd–Ni/KIT-6 was carried out at various operating conditions. • Highest H 2 selectivity and EG conversion were achieved at 773 K and WHSV of 3 h −1 . • Kinetic modeling was done using the power-law and Langmuir-Hinshelwood models.