Preparation of Pd-based catalysts supported on g-C3N4 and their application in the catalytic dehydrogenation of formic acid

g-C₃N₄ (CN-C(NH₄Cl)) supports possessing a remarkably high specific surface area were firstly fabricated via the calcination of melamine with NH₄Cl as an additive. Subsequently, a supported Pd/CN-C(NH₄Cl) catalyst was successfully synthesized through the reduction-impregnation technique. This newly developed catalyst manifests a substantially enhanced catalytic activity in the hydrogen production process from formic acid decomposition. Characterization techniques such as XRD, BET, TEM, XPS and so on reveals that the addition of NH₄Cl was capable of significantly expanding the interlayer spacing of the g-C₃N₄ support, consequently leading to an augmented specific surface area and porosity. This structural alteration effectively facilitates the efficient dispersion of Pd active particles on the surface of the g-C₃N₄ support. Moreover, the CN-C(NH₄Cl) support treated with NH₄Cl is more favorable for the generation of small-sized Pd nanoparticles. In the hydrogen production from formic acid decomposition, the Pd/CN-C(NH₄Cl) catalyst exhibits a conspicuously improved catalytic activity, with the turnover frequency (TOF) value for formic acid decomposition attaining 1407 h⁻¹ at 353 K. This work not only offers a novel approach for catalyst preparation but also deepens the understanding of the relationship between catalyst structure and performance in formic acid decomposition.