Rare earth-doped Ni/MgAl2O4 catalysts prepared via a one-step sol-gel method for steam reforming of volatile organic solvents at low temperatures

To develop efficient steam reforming catalysts that are widely applicable to various volatile organic solvents under low temperatures, rare earth (La, Ce or Pr)-doped Ni/MgAl2O4 were prepared via a novel one-step sol-gel method. Through various characterizations and DFT calculations, it demonstrated that the rare earths not only improved the catalyst structure, but also promoted the dispersion, electron density and D-band center of Ni. Consequently, all the rare earth-doped Ni/MgAl2O4 catalysts exhibited higher catalytic activity in steam reforming of different volatile organic solvents than the Ni/MgAl2O4 in 500-550 degrees C. Thereinto, the 10Ni-2La/ MgAl2O4 performed the best, achieving a conversion efficiency of 97.3% at 550 degrees C for the mixture of toluene, acetone, tetrahydrofuran, and n-hexane. The outstanding performance of Ni-La/MgAl2O4 catalyst arises from the structural compatibility between low-spin La atom and Ni cluster, which enables La to modify Ni dispersion and electronic structure more significantly than Ce or Pr.