ie9b00032_si_001.pdf (553.25 kB)
Dehydrogenation of Isobutane over a Ni–P/SiO2 Catalyst: Effect of P Addition
journal contribution
posted on 2019-04-22, 00:00 authored by Qingqing Zhu, Huanling Zhang, Shan Zhang, Guowei Wang, Xiaolin Zhu, Chunyi LiThe
addition of P to a Ni/SiO2 catalyst greatly changes
the isobutane dehydrogenation performance. The Ni:P ratio is an important
influencing factor for a Ni–P/SiO2 catalyst because
of the formation of different Ni–P compounds. When the Ni:P
ratio equals 1:1, a Ni–P/SiO2 catalyst with Ni2P formed on the surface exhibits an optimum dehydrogenation
performance (an isobutane conversion of 22% and an isobutene selectivity
of 81.3%). The in situ Fourier transform infrared characterization
was performed to determine the adsorption mode of isobutane. Isobutane
is adsorbed onto the Ni–P surface with one H atom in a methyl
group, and the intermediate tends to form isobutene rather than C–C
bond scission. Moreover, the decreased adsorption energy of isobutene
on the Ni2P surface inhibits its further reaction. The
deactivation of a Ni–P/SiO2 catalyst is mainly caused
by the phase transformation from Ni2P to Ni12P5 and coke deposition. Finally, some general rules are
summarized to get a deep understanding of the second component added
to a Ni/SiO2 catalyst.