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.