La-doped Ni/ZrO2 catalyst for the production of H2-rich gas by upgrading vapors coming from pyrolysis of biomass and co-pyrolysis of biomass with plastic

Abstract

The main goal of this work was to develop efficient catalysts for the production of hydrogen-rich gas by upgrading vapors coming from the pyrolysis of biomass and co-pyrolysis of biomass with plastic. A series of nickel catalysts supported on zirconia modified by lanthanum was synthesized. The role of La and its optimal concentration have been studied. The activity of prepared materials was determined with the use of cellulose, poplar, and a mixture of poplar and low-density polyethylene. The analysis of the physicochemical properties of investigated catalysts showed that introducing lanthanum into the zirconia structure resulted in an increase in surface area, pore size, and pore volume. La contributed to the stabilization of tetragonal zirconia. Moreover, its incorporation into the ZrO2 structure led to the formation of stronger interactions between the active phase and support. This facilitated formation of smaller NiO crystallites on the surface of modified materials. It is worth noting that La doped catalysts were more resistant against coke deposition and their deactivation rate was lower than that noticed for parent Ni/ZrO2. It was demonstrated that the addition of polymer (LDPE) to biomass (poplar) resulted in a significant increase in the efficiency of hydrogen production. The highest hydrogen yield was obtained in the presence of the catalyst containing 8% of La.