Open AccessNi–In Synergy in CO2 Hydrogenation to Methanol
Author(s) -
Jiadong Zhu,
Francesco Cannizzaro,
Liang Liu,
Hao Zhang,
Nikolay Kosinov,
Ivo A. W. Filot,
Jabor Rabeah,
Angelika Brückner,
Emiel J. M. Hensen
Publication year - 2021
Publication title -
acs catalysis
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 4.898
H-Index - 198
ISSN - 2155-5435
DOI - 10.1021/acscatal.1c03170
Subject(s) - non blocking i/o , catalysis , x ray photoelectron spectroscopy , dissociation (chemistry) , materials science , transition metal , indium , methanol , oxide , metal , electron paramagnetic resonance , inorganic chemistry , adsorption , chemistry , chemical engineering , organic chemistry , nuclear magnetic resonance , physics , engineering , metallurgy
Indium oxide (In 2 O 3 ) is a promising catalyst for selective CH 3 OH synthesis from CO 2 but displays insufficient activity at low reaction temperatures. By screening a range of promoters (Co, Ni, Cu, and Pd) in combination with In 2 O 3 using flame spray pyrolysis (FSP) synthesis, Ni is identified as the most suitable first-row transition-metal promoter with similar performance as Pd-In 2 O 3 . NiO-In 2 O 3 was optimized by varying the Ni/In ratio using FSP. The resulting catalysts including In 2 O 3 and NiO end members have similar high specific surface areas and morphology. The main products of CO 2 hydrogenation are CH 3 OH and CO with CH 4 being only observed at high NiO loading (≥75 wt %). The highest CH 3 OH rate (∼0.25 g MeOH /(g cat h), 250 °C, and 30 bar) is obtained for a NiO loading of 6 wt %. Characterization of the as-prepared catalysts reveals a strong interaction between Ni cations and In 2 O 3 at low NiO loading (≤6 wt %). H 2 -TPR points to a higher surface density of oxygen vacancy (O v ) due to Ni substitution. X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and electron paramagnetic resonance analysis of the used catalysts suggest that Ni cations can be reduced to Ni as single atoms and very small clusters during CO 2 hydrogenation. Supportive density functional theory calculations indicate that Ni promotion of CH 3 OH synthesis from CO 2 is mainly due to low-barrier H 2 dissociation on the reduced Ni surface species, facilitating hydrogenation of adsorbed CO 2 on O v .