Abstract
H(2) generation from methanol-water mixtures often requires high pressure and high temperature (200-300 °C). However, CO can be easily generated and poison the catalytic system under such high temperature. Therefore, it is highly desirable to develop the efficient catalytic systems for H(2) production from methanol at room temperature, even at sub-zero temperatures. Herein, carbon nanotube-supported Pt nanocomposites are designed and synthesized as high-performance nano-catalysts, via stabilization of Pt nanoparticles onto carbon nanotube (CNT), for H(2) production upon methanol dehydrogenation at sub-zero temperatures. Therein, the optimal Pt/CNT nanocomposite presents the superior catalytic performance in H(2) production upon methanol dehydrogenation at the expense of B(2)(OH)(4), with the TOF of 299.51 min(-1)30 (o)C. Compared with other common carriers, Pt/CNT exhibited the highest catalytic performance in H(2) production, emphasizing the critical role of CNT in methanol dehydrogenation. The confinement of Pt nanoparticles by CNTs is conducive to inhibiting the aggregation of Pt nanoparticles, thereby significantly increasing its catalytic performance and stability. The kinetic study, detailed mechanistic insights, and density functional theory (DFT) calculation confirm that the breaking of O─H bond of CH(3)OH is the rate-controlling step for methanol dehydrogenation, and both H atoms of H(2) are supplied by methanol. Interestingly, H(2) is also successfully produced from methanol dehydrogenation at -10 °C, which absolutely solves the freezing problem in the H(2) evolution upon water-splitting reaction.