Bio-DEE Synthesis and Dehydrogenation Coupling of Bio-Ethanol to Bio-Butanol over Multicomponent Mixed Metal Oxide Catalysts

Abstract

Within the Waste2Fuel project, innovative, high-performance, and cost-effective fuel production methods from municipal solid wastes (MSWs) are sought for application as energy carriers or direct drop-in fuels/chemicals in the near-future low-carbon power generation systems and internal combustion engines. Among the studied energy vectors, C1-C2 alcohols and ethers are mainly addressed. This study presents a potential bio-derived ethanol oxidative coupling in the gas phase in multicomponent systems derived from hydrotalcite-containing precursors. The reaction of alcohol coupling to ethers has great importance due to their uses in different fields. The samples have been synthesized by the co-precipitation method via layered double hydroxide (LDH) material synthesis, with a controlled pH, where the M(II)/M(III) ≈ 0.35. The chemical composition and topology of the sample surface play essential roles in catalyst activity and product distribution. The multiple redox couples Ni2+/Ni3+, Cr2+/Cr3+, Mn2+/Mn3+, and the oxygen-vacant sites were considered as the main active sites. The introduction of Cr (Cr3+/Cr4+) and Mn (Mn3+/Mn4+) into the crystal lattice could enhance the number of oxygen vacancies and affect the acid/base properties of derived mixed oxides, which are considered as crucial parameters for process selectivity towards bio-DEE and bio-butanol, preventing long CH chain formation and coke deposition at the same time.

Developing Benign Ni/g-C3N4 Catalysts for CO2 Hydrogenation: Activity and Toxicity Study

“…The typical bands for sp 2 carbon materials were assigned to G (for graphite) and D (for disordered) at ca. 1570 and 1370 cm –1 , respectively. ,, Using the I D / I G peak intensity ratio, the level of disorder in the bare CN and hybrid material can be characterized as described previously. ,, Moreover, from the I 750 / I 705 ratio (or the I 543 / I 479 ratio), the degree of exfoliation (extent of exfoliation) can be obtained . In all studied catalysts, the I 750 / I 705 ratio indicated the presence of bulk g-C 3 N 4 ; i.e., in the case of pure CN and hybrid Ni/CN, the I 750 / I 705 ratios were ca.…”

“…1570 and 1370 cm –1 , respectively. 5 , 15 , 38 Using the I D / I G peak intensity ratio, the level of disorder in the bare CN and hybrid material can be characterized as described previously. 15 , 16 , 38 Moreover, from the I 750 / I 705 ratio (or the I 543 / I 479 ratio), the degree of exfoliation (extent of exfoliation) can be obtained.…”

“…8 , 14 , 17 , 22 − 25 However, non-noble-metal small clusters or single-atom catalysts (SACs) for the hydrogenation of CO 2 to gas or liquid products, including fuels/drop-in fuels, remain rare. 5 , 26 , 27 For CO 2 methanation reactions, Ni-based catalysts (usually up to 20–30% Ni content) are usually applied in real-scale industrial lines because of their good catalytic performance and for economic reasons. 14 However, their application potential is limited, both at high and low temperatures, because of catalyst coking and Ni nanoparticle (NPs) sintering and poor activity, respectively.…”

“…In recent years, technologies that facilitate the creation of clean energy from renewable and sustainable resources have attracted increased attention. − Much research and pilot work is dedicated to developing efficient, cost-effective synthetic fuel/biofuel production methods in a carbon-neutral or carbon-negative manner. − In search of potential starting candidates for future chemical building blocks, CO 2 , one of the greenhouse gases (GHGs), has captured industrial interest because it is an abundant, inexhaustible, and inexpensive carbon feedstock. ,− At the same time, its hydrogenation to energy-rich products can offer diverse hydrocarbon compounds such as methane, methanol, formic acid, formaldehyde, and C1–C2 ethers. − ,,, Because of the variety of possible applications, including the rubber industry, pharmacy, agriculture, and food technology, they are considered to be highly attractive products. They can also be directly employed as a hydrogen-rich source/energy vector for fuel cells. ,− …”

“…Current research activities focus on a new catalyst preparation methodology that applies solvent-free protocols ideally, atom economy principles, new catalyst compositions, catalyst stability, and durability. Both noble-metal-based catalysts, i.e., Pt, Rh, Ru, and Ir, and transition-metal monometallic catalysts, i.e., Ni and Ni–V bimetallic systems, were found to be effective for the CO 2 valorization process. ,,,− However, non-noble-metal small clusters or single-atom catalysts (SACs) for the hydrogenation of CO 2 to gas or liquid products, including fuels/drop-in fuels, remain rare. ,, For CO 2 methanation reactions, Ni-based catalysts (usually up to 20–30% Ni content) are usually applied in real-scale industrial lines because of their good catalytic performance and for economic reasons . However, their application potential is limited, both at high and low temperatures, because of catalyst coking and Ni nanoparticle (NPs) sintering and poor activity, respectively .…”