Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4985087 | Journal of Colloid and Interface Science | 2017 | 8 Pages |
Stratified nanoporous PtTi (SNP-PtTi) alloys with bimodal size distributions and different components are successfully prepared by selectively dissolving Al atoms followed by removing part of Ti atoms from the PtTiAl precursor alloy. The as-made PtTi alloys have stratified nanoporous architecture with the first order ligaments around 50 nm and the second order smaller ligaments around 6 nm. The SNP-PtTi alloys with different bimetallic ratios exhibit much higher catalytic activity for the hydrolysis of ammonia borane than NP-Pt catalyst. The SNP-Pt65Ti35 alloy shows superior specific activity toward the hydrolytic dehydrogenation of ammonia borane compared with SNP-Pt50Ti50 and -Pt80Ti20, showing an initial turnover frequency of 51.4 mol H2 (mol Pt)â1 minâ1. The activation energy of SNP-Pt65Ti35 was estimated to be about 39.4 kJ molâ1, which was small compared with most of the reported activation energy values in the literature. In addition, the recyclability tests indicate that the SNP-Pt65Ti35 retained 63% of the initial catalytic activity after the fifth run of hydrolysis. The lifetime of SNP-Pt65Ti35 was measured as 16,380 turnovers over 100 h in the hydrolysis of ammonia borane before deactivation. The SNP-PtTi alloys show potential application prospect in the field of online hydrogen production due to the high catalytic performance and the facile preparation.
Graphical abstractStratified nanoporous PtTi (SNP-PtTi) alloys with different bimetallic ratios are successfully fabricated by first selectively dissolving Al atoms followed by removing part of Ti atoms from the PtTiAl precursor alloy. The as-prepared SNP-PtTi alloys consist of interconnected bimodal nanoporous architecture with two order pore/ligament distributions and interconnected hollow channels extending in all three dimensions. Compared with NP-Pt catalyst, SNP-PtTi alloys show superior catalytic activities toward AB hydrolysis reaction in virtue of the perfect combination of unique stratified nanoporous architecture and alloying effect.Download high-res image (112KB)Download full-size image