title: Stratified nanoporous PtTi alloys for hydrolysis of ammonia borane.
abstract: 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 50nm and the second order smaller ligaments around 6nm. 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-Pt65Ti35alloy shows superior specific activity toward the hydrolytic dehydrogenation of ammonia borane compared with SNP-Pt50Ti50and -Pt80Ti20, showing an initial turnover frequency of 51.4mol H2(molPt)-1min-1. The activation energy of SNP-Pt65Ti35was estimated to be about 39.4kJmol-1, which was small compared with most of the reported activation energy values in the literature. In addition, the recyclability tests indicate that the SNP-Pt65Ti35retained 63% of the initial catalytic activity after the fifth run of hydrolysis. The lifetime of SNP-Pt65Ti35was measured as 16,380 turnovers over 100h 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.
authors.affiliation: Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China.
authors.forename: Qiuxia
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China. Electronic address: chm_xucx@ujn.edu.cn.
authors.forename: Caixia
authors.initials: C
authors.lastname: Xu
keywords: Ammonia borane; Dealloying; Hydrolysis; Nanoporous; Platinum