Heterogeneous La and CeOx co-promoted SAPO-11 catalyst for catalytic upgrading of cellulose-derived volatile and methanol into hydrocarbon-rich fuels

Abstract

In this paper, a series of La–Ce co-doped SAPO-11 catalysts with various La to Ce ratio were developed via wet impregnation method then employed in catalytic cellulose and methanol co-pyrolysis to produce hydrocarbon-rich biofuels. Comprehensive characterization technologies including X-ray diffraction, X-ray photoelectron spectroscopy, N2 physisorption, scanning electron microscope, transmission electron microscope, ammonia temperature-programmed desorption, Pyridine-infrared, and thermal gravimetric analyzer, were conducted to unveil the physicochemical properties, structure properties and acidity of as-prepared catalysts. Additionally the product content; aromatic selectivity and synergetic effect were also investigated. Additionally possible conversion pathway, deactivation mechanism and reusability were also deduced. La and Ce showed a certain synergetic effect and exhibited superior catalytic deoxygenation activity due to La–O and Ce-Ox species, suitable Brønsted acidity, abundant oxygen vacancies and enhanced mesopores structure, which was facilitated to promote the selectivity of hydrocarbon. Higher La content was fascinated to generate furans and ketones compounds, due to lower Brønsted acid site and smaller specific surface area. In contrast, higher CeOx content was beneficial to hydrocarbon formation via Diels-Alder reaction and dehydro-aromatization due to higher Brønsted acid site, total acidity, higher specific surface area, mesoporous pore volume as well as strong oxygen affinity of CeOx. The maximum proportion hydrocarbon, aromatics and minimum contents coke was obtained over 1La–1Ce/SAPO-11 were 77.96 %, 55.82 % and 9.81 %, respectively. Additionally, 1La–1Ce/SAPO-11 catalyst exhibited outstanding reusability and stability after four cycles; nearly ∼96 % relative content of hydrocarbon was maintained after regeneration test. Hence, the insight into the synergetic catalysis between La and CeOx species could provide a new potential possible pathway for design and synthesized efficient and eco-friendly bimetallic catalyst for selective catalytic deoxygenation organic solid waste biomass for valuable chemicals.