Bioacid Hydroconversion over Co, Ni, Cu Mono- and Indium-doped Bimetallic Catalysts

Abstract

Caprylic acid (CA) as model reactant was selectively reduced in a flow-through reactor in hydrogen stream at 21 bar total pressure and 240-360°C over alumina loaded with the adjacent Co, Ni, Cu host and In guest metals. The main target of this research is the recognition of efficient cobalt catalysts for carboxylic group hydroconversion compared to more familiar nickel and copper composites. The catalysts were activated in H 2 flow at 21 bar and 450°C. By variation of main metal or modification with indium, mono-or bimetallic catalysts can be obtained with low hydrodecarbonylation activity and high alcohol selectivity. These composites have higher hydrodeoxygenation (HDO) activity and alcohol selectivity than the conventional commercial catalysts applied for fatty alcohol production. Great variety of catalytic behavior indicates complexity of the surface reactions determined by several interacting factors.

Recent Developments of Heterogeneous Catalysts for Hydrogenation of Carboxylic Acids to their Corresponding Alcohols

“…Harnos, Onyestyák and co‐workers investigated combination of supported Ni and In 2 O 3 in gas‐phase hydrogenation of carboxylic acids such as octanoic acid, acetic acid and decanoic acid to the corresponding alcohols (Table , entries 1–7), and they found that modification of Ni metal with In 2 O 3 improved selectivity and activity. Also, the performance was superior to the Adkins catalyst, a standard catalyst of Cu−Cr type catalyst for hydrogenation of carboxylic acid and esters.…”

Turning a Methanation Catalyst into a Methanol Producer: In-Co Catalysts for the Direct Hydrogenation of CO2 to Methanol

“…When compared against the parent monometallic catalyst, a systematic suppression of the hydro-decarbonylation reaction was found. [39][40][41] By analogy, we propose that indium poisons the surface of metallic cobalt, hindering its total hydrogenation activity (approximately 80% CO2 conversion on metallic Co vs. 19% on In@Co-1). This surface modification may also prevent methane formation due to a slower hydrogenolysis rate of the C-O bond compared to the desorption rate of the CO and CH3OH intermediates.…”