Synergistic Pt-WO3 Dual Active Sites to Boost Hydrogen Production from Ammonia Borane

Abstract

Development of synergistic heterogeneous catalysts with active sites working cooperatively has been a pursuit of chemists. Herein, we report for the first time the fabrication and manipulation of Pt-WO 3 dual-active-sites to boost hydrogen generation from ammonia borane. A combination of DFT calculations, structural characterization, and kinetic (isotopic) analysis reveals that Pt and WO 3 act as the active sites for ammonia borane and H 2 O activation, respectively. A trade-off between the promoting effect of WO 3 and the negative effect of decreased Pt binding energy contributes to a volcano-shaped activity, and Pt/CNT-5W delivers a 4-fold increased activity of 710.1 mol H2 $mol Pt À1 $min À1 . Moreover, WO 3 is suggested to simultaneously act as the sacrificial site that can divert B-containing by-products away from Pt sites against deactivation, yielding an increase from 24% to 68% of the initial activity after five cycles. The strategy demonstrated here could shed a new light on the design and manipulation of dual-active-site catalysts.

Crystal facet effects of platinum single-atom catalysts in hydrolytic dehydrogenation of ammonia borane

“…Additionally, the turnover frequency (TOF) of Pt 1 /Co 3 O 4 -c in AB hydrolytic dehydrogenation was about 6035 mol H 2 mol Pt −1 min −1 , which was higher than that of Pt 1 /Co 3 O 4 -t (2143 mol H2 mol Pt −1 min −1 ) and Pt 1 /Co 3 O 4 -o (1719 mol H 2 mol Pt −1 min −1 ) and outperformed almost all supported Pt-based catalysts ever reported (Fig. 3b, e and Table S2†), 10,25,27,28,32–34,41–49 confirming that both the addition of Pt single-atoms and the interaction between Pt and Co 3 O 4 exposed surfaces affected the catalytic activity.…”

“…As shown in Fig. S5, S2 †), 10,25,27,28,[32][33][34][41][42][43][44][45][46][47][48][49] conrming that both the addition of Pt single-atoms and the interaction between Pt and Co 3 O 4 exposed surfaces affected the catalytic activity. Furthermore, to investigate the kinetics of AB hydrolytic dehydrogenation, experiments were conducted at different temperatures with Pt 1 /Co 3 O 4 -x (x ¼ c, t, o) catalysts (Fig.…”

Recent Advances in Noble Metal Catalysts for Hydrogen Production from Ammonia Borane

“…These experimental results exhibited that the validity of partly replacing Pt by a first-row transition metal on designing superior property heterogeneous nanocatalysts for AB hydrolytic. Chen et al [113] designed Pt-WO 3 double active site catalyst to boost the catalytic hydrolysis of AB. Figure 9 showed the hydrolysis mechanism of AB on Pt double activity.…”

Magnetically Isolable Pt0/Co3O4 Nanocatalysts: Outstanding Catalytic Activity and High Reusability in Hydrolytic Dehydrogenation of Ammonia Borane

“…Significant achievement has been obtained in catalyzing the hydrogen evolution from the hydrolysis of AB at ambient temperature by using transition-metal nanoparticles (NPs). , Platinum turns to be one of the highest active noble metals showing high turnover frequency (TOF) for the hydrolysis of AB at room temperature. − Unfortunately, the high cost of platinum limits its large-scale use as a catalyst for hydrogen generation through the hydrolysis of AB. While continuous endeavor has been made to improve the catalytic activity of non-noble metals, there is a high demand for maximizing the reusability and, thus, ultimately lowering the cost of Pt-based catalysts.…”