Pd Nanoparticles Supported on N-Doped TiO<sub>2</sub> Nanosheets: Crystal Facets, Defective Sites, and Metal–Support Interactions Boost Reforming of Formaldehyde Solution for Hydrogen Production
Xiaogang Liu, Xin Zhang, Wenjie Chen
Abstract
To produce H2 from formaldehyde (HCHO), dehydrogenation offers an alternative approach to future hydrogen-based energy sources, but the unsatisfactory efficiency hinders its practical application. Here, ultrafine Pd nanoparticle (NP) decorated N-doped TiO2 nanosheets exposed with (001) facet catalysts (denoted as Pd/TiO2–x) have been prepared and exhibit superior H2 production performance from alkaline HCHO aqueous solution. Under our current conditions, the Pd/TiO2–x catalyst with a Pd loading of 1 wt % exhibits a H2 production rate of 183.77 mL/min/g, which is 1.75 and 3.66 times that of Pd/TiO2 and Pd NPs, respectively. Based on the results of Fourier transform infrared spectroscopy (FTIR), Raman, and liquid-phase electron paramagnetic resonance (EPR) spin-trapping experiments, the excellent H2 generation of Pd/TiO2–x can be attributed to the synergistic contribution among the reactive crystal facets, defective sites, and metal–support interactions in boosting the breakage of C–H bonds in HCHO, dissociation of H2O, and ultimately the formation of H2. This work is expected to provide a paradigm of an efficient catalyst to produce H2 from HCHO/H2O solution.