TY - JOUR
T1 - Heterogeneous catalyst stability during hydrodenitrogenation in supercritical water
AU - Jocz, Jennifer N.
AU - Savage, Phillip E.
AU - Thompson, Levi T.
N1 - Funding Information:
The authors gratefully acknowledge contributions from Dr. David Hietala and financial support from the University of Michigan. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE 1256260.
Funding Information:
The authors gratefully acknowledge contributions from Dr. David Hietala and financial support from the University of Michigan. This material is based upon work supported by the N ational Science Foundation Graduate Research Fellowship under Grant No. DGE 1256260.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/7/1
Y1 - 2021/7/1
N2 - The catalytic removal of heteroatoms from renewable bio-oils in supercritical water (SCW) is challenged by the lack of sufficiently stable catalysts. We identified a library of catalytic materials that are thermodynamically stable under hydrodenitrogenation (HDN) conditions, based on oxygen fugacity–pH diagrams. From among these, we selected a Pt/TiO2 catalyst for HDN of propylamine in SCW at 380–500 °C and 22–38 MPa. Flow experiments with aqueous feeds of formic acid, ammonia, and propylamine were designed to isolate interactions between the catalyst, the SCW solution, and the reactants and products. The Pt/TiO2 catalyst was highly active and experienced negligible dissolution at 500 °C, 2% Pt loss at 380 °C, and no changes in oxidation state. Overall, the experimentally observed hydrothermal stabilities of the catalyst agreed with the thermodynamic stabilities predicted. The results and methodology applied in this work may be useful to identify and design catalysts for bio-oil upgrading in hydrothermal media.
AB - The catalytic removal of heteroatoms from renewable bio-oils in supercritical water (SCW) is challenged by the lack of sufficiently stable catalysts. We identified a library of catalytic materials that are thermodynamically stable under hydrodenitrogenation (HDN) conditions, based on oxygen fugacity–pH diagrams. From among these, we selected a Pt/TiO2 catalyst for HDN of propylamine in SCW at 380–500 °C and 22–38 MPa. Flow experiments with aqueous feeds of formic acid, ammonia, and propylamine were designed to isolate interactions between the catalyst, the SCW solution, and the reactants and products. The Pt/TiO2 catalyst was highly active and experienced negligible dissolution at 500 °C, 2% Pt loss at 380 °C, and no changes in oxidation state. Overall, the experimentally observed hydrothermal stabilities of the catalyst agreed with the thermodynamic stabilities predicted. The results and methodology applied in this work may be useful to identify and design catalysts for bio-oil upgrading in hydrothermal media.
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U2 - 10.1016/j.cattod.2020.07.064
DO - 10.1016/j.cattod.2020.07.064
M3 - Article
AN - SCOPUS:85090166408
VL - 371
SP - 171
EP - 178
JO - Catalysis Today
JF - Catalysis Today
SN - 0920-5861
ER -