Jia Jia, O'Brien Paul G, He Le, Qiao Qiao, Fei Teng, Reyes Laura M, Burrow Timothy E, Dong Yuchan, Liao Kristine, Varela Maria, Pennycook Stephen J, Hmadeh Mohamad, Helmy Amr S, Kherani Nazir P, Perovic Doug D, Ozin Geoffrey A
Department of Materials Science & Engineering University of Toronto 184 College Street Toronto Ontario M5S 3E4 Canada.
Materials Chemistry and Nanochemistry Research Group Solar Fuels Cluster Department of Chemistry University of Toronto 80 St. George Street Toronto Ontario M5S 3H6 Canada.
Adv Sci (Weinh). 2016 Jul 5;3(10):1600189. doi: 10.1002/advs.201600189. eCollection 2016 Oct.
The reverse water gas shift (RWGS) reaction driven by NbO nanorod-supported Pd nanocrystals without external heating using visible and near infrared (NIR) light is demonstrated. By measuring the dependence of the RWGS reaction rates on the intensity and spectral power distribution of filtered light incident onto the nanostructured Pd@NbO catalyst, it is determined that the RWGS reaction is activated photothermally. That is the RWGS reaction is initiated by heat generated from thermalization of charge carriers in the Pd nanocrystals that are excited by interband and intraband absorption of visible and NIR light. Taking advantage of this photothermal effect, a visible and NIR responsive Pd@NbO hybrid catalyst that efficiently hydrogenates CO to CO at an impressive rate as high as 1.8 mmol gcat h is developed. The mechanism of this photothermal reaction involves H dissociation on Pd nanocrystals and subsequent spillover of H to the NbO nanorods whereupon adsorbed CO is hydrogenated to CO. This work represents a significant enhancement in our understanding of the underlying mechanism of photothermally driven CO reduction and will help guide the way toward the development of highly efficient catalysts that exploit the full solar spectrum to convert gas-phase CO to valuable chemicals and fuels.
展示了由负载在NbO纳米棒上的Pd纳米晶体驱动的逆水煤气变换（RWGS）反应，该反应在不使用外部加热的情况下利用可见光和近红外（NIR）光进行。通过测量RWGS反应速率对入射到纳米结构的Pd@NbO催化剂上的滤光光强度和光谱功率分布的依赖性，确定RWGS反应是通过光热激活的。也就是说，RWGS反应是由Pd纳米晶体中的电荷载流子热化产生的热量引发的，这些电荷载流子通过可见光和近红外光的带间和带内吸收而被激发。利用这种光热效应，开发了一种可见光和近红外响应的Pd@NbO混合催化剂，该催化剂能以高达1.8 mmol gcat-1 h-1的惊人速率有效地将CO氢化为CO。这种光热反应的机制涉及Pd纳米晶体上的H解离以及随后H向NbO纳米棒的溢出，在此之后，吸附的CO被氢化为CO。这项工作显著增进了我们对光热驱动CO还原潜在机制的理解，并将有助于指导开发高效催化剂的方向，这些催化剂利用整个太阳光谱将气相CO转化为有价值的化学品和燃料。
