Fabrication of Pd/Mg2P2O7 via a Struvite-Template Way from Wastewater and Application as Chemoselective Catalyst in Hydrogenation of Nitroarenes

Graphical One man‘s trash is another man‘s treasure : A novel template strategy allows fibrous struvite—a composite Pd/Mg 2 P 2 O 7 with a mesoporous structure and an ultrahigh surface area—to be synthesized from wastewater. The prepared Pd/Mg 2 P 2 O 7 nanowires showed excellent performance in the selective hydrogenation of nitrobenzenes. This strategy provided a new pathway for synthesizing highly efficient catalysts as well as a solution for alleviate eutrophic pollution caused by N- and P-containing substances in wastewater. A highly efficient heterogeneous catalyst Pd/Mg 2 P 2 O 7 was fabricated by combining palladium nanoparticles (PdNPs) and mesoporous Mg 2 P 2 O 7 fibers/rods. Mg 2 P 2 O 7 fibers with ultra-high specific surface area were prepared from struvite as templates, which were synthesized from waste water containing N- and P-containing pollutants. This strategy provided a novel pathway for developing advanced catalysts from eutrophication-polluted water. The composite Pd/Mg 2 P 2 O 7 showed brilliant performance in selective hydrogenation of nitro aromatics to give anilines. As an example of nitrobenzene hydrogenation, the conversion to aniline and selectivity were found to reach almost 100 % at a temperature of T =90 °C and under a pressure of P =2.0 MPa. The superior performance was found to originate from PdNPs, which were boosted by electron transfer afforded by the nanofiber Mg 2 P 2 O 7 supports. The favorable adsorption of withdrawing groups (−NO 2 ) was realized by synergistic effects between Pd and oxygen vacancies provided by pyrolysis of struvite. The catalyst remained stable after cycles of reuse with little degradation in catalytic performance.