Hydrogen Production from Formic Acid Vapour over a Pd/C Catalyst Promoted by Potassium Salts: Evidence for Participation of Buffer-Like Solution in the Pores of the Catalyst
Full article
| Общее |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Original
|
| Journal |
Applied Catalysis B: Environmental
ISSN: 0926-3373
, E-ISSN: 1873-3883
|
| Output data |
Year: 2014,
Volume: 160-161,
Pages: 35-43
Pages count
: 9
DOI:
10.1016/j.apcatb.2014.05.004
|
| Tags |
Doping, Formic acid, Hydrogen production, Palladium, Potassium formate |
| Authors |
Jia Lijun
,
Bulushev Dmitri A.
,
Beloshapkin Sergey
,
Ross Julian R.H.
|
| Affiliations |
| 1 |
University of Limerick
|
| 2 |
University of Limerick
|
|
Funding (3)
|
1
|
Science Foundation Ireland
|
06/CP/E007
|
|
2
|
Government of Ireland
|
|
|
3
|
China Scholarship Council
|
|
Doping a 1 wt.% Pd/C catalyst with alkali metal carbonates has a very significant promotional effecton its activity in hydrogen production from the decomposition of formic acid vapour (2 vol.%, 1 bar),potassium and caesium carbonates giving the largest effects. The K carbonate species present on the freshcatalysts react with formic acid to form formate ions, these being dissolved in a formic acid/water solutioncondensed in the pores of the support. The steady-state activities of the samples containing formate ionswere 1–2 orders of magnitude greater than those of the unpromoted Pd/C and CO content was lowerthan 30 ppm. The activation energies for the reaction increased with doping from 66 to 88–99 kJ mol−1,relatively independent of the cation of the dopant. Similar but lesser effects were found with unsupportedPd nanocrystals doped with K carbonate. The rate-determining step for the promoted samples appearsto be the decomposition of formate ions on the Pd surface.