Ni decorated three-dimension hierarchical pyramidal ZrO2–Al2O3 nanoporous sheets for methane production

Abstract

ZrO2–Al2O3 nanocomposites were synthesized by a modified co-precipitation method and loaded with 5%Ni as catalysts for methane production via n-heptane cracking. The as-synthesized nanocomposites were characterized by several techniques such as XRD, N2 adsorption-desorption, XPS, TEM, SEM, AFM, TGA, DTG, NH3 -TPD and Raman analysis. The XRD results confirmed the synthesis of amorphous γ alumina and hexagonal phase of zirconium alumina oxide (Zr5Al3O0.5) solid solution. XRD and SEM analyses showed additional small size Related to monoclinic phase of ZrO2 particles loaded on the Al2O3 surface. BET analyses confirmed the ZrO2–Al2O3 formation in mesoporous sheets structure. TEM images of the neat alumina, 10 ZA and their corresponding Ni loaded samples (Ni@10 ZA) revealed well-defined 3D hierarchical pyramidal structures with a height about 200 nm. All catalysts under this study exhibited high tendency to favor methane production via n-heptane cracking. At higher reaction temperatures, Ni@10 ZA catalyst exhibited higher cracking activity compared to the other prepared catalysts under this investigation which confirmed by NH3 -TPD analysis. A promising yield of methane was achieved at about 88 % coupled with 94.71 % selectivity at reaction temperature of 400 °C. Herein, the data collected through this research work revealed that Ni@10 ZA is a promising candidate for methane production via n-heptane cracking.