Selective Hydrogenation of Acetylene to Ethylene over the Surface of Sub-2 nm Pd Nanoparticles in Miscanthus sinensis-Derived Microporous Carbon Tubes

As one of the organic carbon-rich feedstocks, Miscanthus sinensis is an interesting candidate for producing many high-value materials and chemicals. In this study, M. sinensis-derived activated carbon (msAC) particles with ca. 3.4 nm average pore size have been prepared by a simple carbonation method for supporting Pd nanoparticles (NPs) to hydrogenate acetylene. Catalytic test results showed that the 0.25% Pd/msAC catalyst could convert ∼99.9% of acetylene with ∼99.9% of ethylene selectivity. The life test result strongly demonstrated that the catalyst had a good durability for long-term (>100 h) acetylene hydrogenation with high conversion (∼99.9%) and ethylene selectivity (∼93.1%) at 260 °C with a space velocity of 80,000 h–1. The characterization results indicated that the msAC with the micro- and nanoscale pore structure and uniformly distributed oxygen-containing functional groups could efficiently disperse Pd nanoparticles and promote their Pd (111) crystal plane exposure. The above structure nature was co-contributing to the catalyst to choose the energetically favorable path for efficient acetylene hydrogenation and ethylene desorption. This work opens up valuable insights into the high-value utilization of M. sinensis biomass to design an efficient isolated Pd NP catalyst.