Hydrogen Production via Acetic Acid Steam Reforming over HZSM-5 and Pd/HZSM-5 Catalysts and Subsequent Mechanism Studies

Abstract

Acetic acid (HOAc) was selected as a bio-oil model compound for the steam reforming of bio-oil for hydrogen production. The influence of temperature and steam-to-carbon ratio (S/C) on the steam reforming of HOAc over hydrogen-type Zeolite Socony Mobil-5 (HZSM-5) and the catalyst with added Pd (Pd/HZSM-5) have been investigated in a fixedbed reactor. Brunauer-Emmett-Teller surface area measurements, scanning electron microscopy, and transmission electron microscopy were performed to characterize the texture and structure of the catalysts. Upon addition of Pd to HZSM-5, the selectivity of the products was modified and the H 2 yield was greatly increased. The hydrogen yield and potential hydrogen yield from the steam reforming of HOAc were as high as 60.2% and 87.5%, respectively, under optimized reaction conditions. Both the conversion of HOAc and the H 2 yield over Pd/HZSM-5 were significantly enhanced with increasing S/C ratio and reaction temperature below 600 C, whereas the H 2 yield did not significantly increase at temperatures above 600 C. The mechanism of HOAc decomposition on the Pd(111) surface was calculated via density functional theory. The optimal decomposition route was found to be CH

Comparative Kinetic Monte Carlo Study of Acetic Acid Decomposition to Surface Carbon Species and Undesirable Byproducts on Pd(100) and Pd/Au(100) from Density Functional Theory-Based Calculations

“…Recently, acetic acid decomposition has drawn the attention of increasing researchers. Acetic acid decomposition catalyzed by photocatalysts has been investigated as a typical eco-friendly representative of treatment for air pollution and wastewater. − Additionally, steam reforming of acetic acid is studied as a model substance in bio-oil for biomass-derived hydrogen production, which can be widely used in fuel cells and combustion engines as one of the promising clean and renewable energy resources. − Because of its wide application, acetic acid decomposition on many different catalysts have been examined, such as Ag, Pt, Rh, Co, Pt/ZrO 2 , CuO/Rutile, TiO 2 , Pt/TiO 2 , , Pt/CeO 2 , MgO, , and so on. Great efforts also have been devoted to acetic acid decomposition on palladium, − since acetic acid is one important reactant of vinyl acetate (VA) synthesis from ethylene acetoxylation, and it is also one possible source of surface carbon formation and many sorts of undesirable byproducts generated during VA synthesis from ethylene acetoxylation, according to the following equation: − …”