Amin Osatiashtiani

University of Leeds

The catalytic performance of a monometallic Ni/Al2O3 and three bimetallic Ni-Cu catalysts (with Cu loading of 2.5, 5, and 7.5 mol%, respectively) for the (sorption-enhanced) steam methane reforming reaction was evaluated. Physico-chemical characterization of the materials confirmed the formation of Ni-Cu alloy and the even distribution of active me...

γ-Valerolactone (GVL) is a versatile chemical derived from biomass, known for its uses such as a sustainable and environmentally friendly solvent, a fuel additive, and a building block for renewable polymers and fuels. Researchers are keenly interested in the catalytic transfer hydrogenation of levulinic acid and its esters as a method to produce G...

Potassium exchanged Sn-β and Sn-USY zeolites have been tested for the transformation of various aldoses (hexoses and pentoses), exhibiting outstanding catalytic activity and selectivity toward methyl lactate. Insights into the transformation pathways using reaction intermediates—dihydroxyacetone and glycolaldehyde—as substrates revealed a very high...

In this work, we report a novel and green method for the synthesis of hierarchical nanozeolites for the hydro-deoxygenation of oleic acid to diesel-range hydrocarbons. Hierarchical nanozeolites based on HZSM-5 and HBEA with appropriate mesopores (8-20 nm) were synthesised through the surface silanisation of zeolitic seeds. In this method, organosil...

Recyclable PdCu single atom alloys supported on Al2O3 were applied to the selective hydrogenation of crotonaldehyde to elucidate the minimum number of Pd atoms required to facilitate the sustainable transformation of an α,β-unsaturated carbonyl molecule. It was found that, by diluting the Pd content of the alloy, the reaction activity of Cu nanopar...

Valerolactone (GVL) is a renewable and versatile platform chemical derived from sustainable carbon feedstocks. The cascade conversion of levulinic acid into GVL requires Brønsted and Lewis acid catalysed reactions. Here, a dual‐catalyst bed configuration is demonstrated that promotes synergy between Brønsted acid sites in sulfated zirconia (SZ) and...

Potassium modified acid–base bifunctionalized MgAl-SBA-15 for mild aldol condensation of furfural and acetone to high-quality jet-fuel range or chemical intermediates.

In this work, we have investigated the complicated reaction network of biomass catalytic fast pyrolysis, particularly the decomposition of the key cellulose pyrolysis intermediate, levoglucosan. Fast pyrolysis of levoglucosan using a Py-GC-MS-FID system in the presence of HZSM-5 suggested that furan and furfural are key intermediates to aromatic hy...

γ-Valerolactone (GVL) is an important bio-derived platform molecule whose atom- and energy efficient, and scalable, catalytic synthesis is highly desirable. Catalytic transfer hydrogenation (CTH) of ethyl levulinate (EL) to γ-valerolactone (GVL) has been selectively performed in batch and continuous flow over ZrO2/SBA-15 solid acid catalysts. Tunin...

Single-atom catalysts serve as a skilful control of precious metals on heterogenous catalysts where all active sites are accessible for catalytic reactions. Here we report the adoption of PdCu single-atom alloys supported on alumina for the selective hydrogenation of furfural. This is a special class of an atom efficient, single-site catalyst where...

This work explored formulation of mesoporous silicas pellets using a range of bentonite and colloidal silica (LUDOX), aiming to optimise the binder composition that minimises any deteriorating effects on adsorption performance, while provides an adequate mechanical integrity. Thermogravimetric analysis, scanning electron microscopy, and dynamic mec...

Biomass-derived carboxylic acids (e.g. acetic acid AcOH and formic acid FA) are a green and low-cost hydrogen source to replace hazardous H2 gas in in-situ hydrogenation processes. To date, bio-acids dehydrogenation has been mainly conducted using noble metal catalysts which would negatively impact the process economy, thus development of efficient...

Herein, for the first time, we demonstrate a novel continuous flow process involving the application of tetralin as a hydrogen donor solvent for the catalytic conversion of oleic acid to diesel-like hydrocarbons, using an efficient and stable carbon-supported bimetallic PdCu catalyst. Using Pd60Cu40/C, where 60:40 is the molar ratio of each metal,...

BACKGROUND Modern day scientific endeavour strives towards global sustainability through the smart utilisation of renewable resources as base materials for chemicals. Until now, the most common commercial process to produce levulinic acid (a mass‐produced platform chemical) depends on a two‐stage mineral acid‐catalysed reaction, which generates har...

The formation of copper-based catalysts ranging from nanoparticles to isolated and dimeric Cu species supported on nanophased alumina is reported and utilised for the catalytic liquid-phase hydrogenation of furfural. The materials were synthesised via wet impregnation using various copper precursors (nitrate, acetate and sulphate) at two different...

Hierarchical Cu2O nanospheres with a Pompon Dahlia‐like morphology were prepared by a one‐pot synthesis employing electrostatic self‐assembly. Nanocomposite analogues were also prepared in the presence of reduced graphene oxide (rGO). Photophysical properties of the hierarchical Cu2O nanospheres and Cu2O/rGO nanocomposite were determined, and their...

Biorefineries are a new concept in chemical manufacturing in which naturally occurring, sustainable biomass resources such as forestry and agricultural waste are converted to diverse fuel and chemical product streams, akin to the processing of non‐renewable fossil fuels by petrochemical refineries. Polysaccharides are attractive potential feedstock...

Pyrolysis bio-oils contain significant amounts of carboxylic acids which limit their utility as biofuels. Ketonisation of carboxylic acids within biomass pyrolysis vapours is a potential route to upgrade the energy content and stability of the resulting bio-oil condensate, but requires active, selective and coke-resistant solid acid catalysts. Here...

Bio-acids produced from biomass fast pyrolysis are regarded as alternative hydrogen source for upgrading bio-oil into transport fuels. In this work, the hydrogen donation performance of acetic acid (AcOH) and formic acid (FA) were evaluated over the transition metal facet in comparison with H2 gas, using Density Functional Theory (DFT) modelling. I...

Catalytic transesterification of triglycerides and esterification of free fatty acids underpins sustainable biodiesel production, wherein efficient heterogeneous catalysts are sought to replace mineral acids. A robust, magnetic core-shell SO4/Mg-Al-Fe3O4 catalyst was synthesised by stepwise co-precipitation, encapsulation, and surface functionalisa...

The thermal sintering under oxidative conditions of Rh nanoparticles supported on oxides characterized by very di↵erent oxygen storage capacities (OSC) and labilities was studied at 750 and 850 C. Under sintering conditions, significant particle growth occurred for Rh/-Al 2 O 3 (up to 120% at 850 C). In striking contrast, Rh/ACZ (alumina-ceria-zirc...

The effects of the metal oxide support on the activity, selectivity, resistance to carbon deposition and high temperature oxidative aging on the Rh-catalyzed dry reforming of methane (DRM) were investigated. Three Rh catalysts supported on oxides characterized by very different oxygen storage capacities and labilities (γ-Al2O3, alumina-ceria-zircon...

Bimetallic Pd x Ni (100-x) and Pd x Cu (100-x) structures of a wide compositional range supported on activated carbon were synthesised via a simple, cheap and commercially relevant method. The surface and bulk properties of both the bimetallic structures and their monometallic counterparts were determined via STEM-EDS, TEM, XPS, powder XRD, N 2 por...

The catalytic cracking of polyolefinic waste materials over solid acid catalysts, such as zeolites, is a promising process for the production of useful fuels and chemicals. However, the inherent diffusional constraints of the microporous zeolites restrict the access of bulky polyolefin molecules to the active site, therefore limiting their effectiv...

Controlling the thickness of zirconia monolayers coated over SBA-15 offers an effective way to tune catalytic performance for the acid-mediated and hydrogen transfer (Meerwein Ponndorf Verley, MPV) cascade transformation of furfural to γ-valerolactone. Complementary mechanistic and kinetic modelling establishes the existence of the two distinct zir...

Mesoporous silicas were synthesized via a surfactant-templated sol-gel route using castor oil as the templating agent under acidic medium. The resulting silicas were subsequently amine functionalized with 3-aminopropyltriethoxysilane (NH 2 -MTS), [3-(2-aminoethylamino)-propyl]trimethoxysilane (NN-MTS), and [3-(diethylamino)propyl]trimethoxysilane(D...

Crude pyrolysis bio-oil contains significant quantities of carboxylic acids which limit its utility as a biofuel. Vapour phase ketonisation of organic acids contained within biomass fast-pyrolysis vapours offers a potential pre-treatment to improve the stability and energy content of resulting bio-oils formed upon condensation. Zirconia is a promis...

Several families of catalysts characterized by different types of acid and base sites were developed to steer regioselectivity in the aldol condensation of unsymmetrical ketones. The catalysts were propyl sulfonic-acid (PrSO3H) functionalized SBA-15 with various acid loadings and with or without hydrophobization by octyl groups (Oc); isomorphously...

Functionalization of mesoporous SBA-15 frameworks by transition metal oxides offers a flexible route to fabricate new heterogeneous catalysts. Here, an inorganic-organic hybrid nanoporous catalyst H5PW10V2O40@VOx/SBA-15-NH2, was prepared and utilized as an efficient, eco-friendly, and recyclable catalyst for the one-pot, multi-component synthesis o...

A magnetic inorganic-organic catalyst, PTA@Fe3O4/EN-MIL-101 (EN = ethylenediamine, PTA = phosphotungstic acid) was fabricated and characterized by XRD, HRTEM, FESEM, UV–vis, TGA-DTA, FT-IR, XPS and porosimetry. PTA retained the parent Keggin structure upon dispersion throughout the amine-functionalized chromium terephthalate metal-organic framework...

The one-pot conversion of xylose into γ-gammavalerolactone in 2-propanol over bifunctional Zr-Al-Beta zeolites, prepared via a post-synthetic route, was optimized in terms of both catalyst synthesis and reaction conditions. In the catalyst preparation, the use of Zr(NO3)4 as zirconium source as well as the tuning of the amount of water used during...

Functionalization of mesoporous SBA-15 frameworks by transition metal oxides offers a flexible route to fabricate new heterogeneous catalysts. Here, an inorganic-organic hybrid nanoporous catalyst H5PW10V2O40@VOx/SBA-15-NH2, was prepared and utilized as an efficient, eco-friendly, and recyclable catalyst for the one-pot, multi-component synthesis o...

New insight was gained into the acidity-reactivity relationships of sulfated zirconia (SZ) catalysts prepared via (NH4)2SO4 impregnation of Zr(OH)4 for propanoic acid esterification with methanol. A family of systematically related SZs was characterized by bulk and surface analyses including XRD, XPS, TGA-MS, N2 porosimetry, temperature-programmed...

Fast pyrolysis bio-oils possess unfavourable physicochemical properties and poor stability, due in large part to the presence of carboxylic acids, which hinders their use as biofuels. Catalytic esterification offers an atom and energy efficient route to upgrade pyrolysis bio-oils. Propyl sulfonic acid silicas are active for carboxylic acid esterifi...

The depletion of fossil fuel resources and concerns over climate change and CO 2 emission have driven the quest for clean catalytic technology for the production of green and renewable energy. Among the future sustainable energy platforms, biomass derived from nonfood sources of lignocellulose, sugars, and triglycerides is the only sustainable sour...

γ-valerolactone (GVL) is an important intermediate chemical with a wide range of applications as fuel, fuel additive and as a green solvent which has received a great deal of attentions from both academia and industry. This review aims to summarise the advances in conversion of renewable feedstocks into GVL through heterogeneous catalytic transfer...

A family of faujasite (FAU) zeolites with different Si:Al ratio, and/or hierarchical porosity introduced via post-synthetic alkaline desilication treatment, have been evaluated as solid acid catalysts for esterification pretreatments of pyrolysis bio-oil components. Acetic acid esterification with aliphatic and aromatic alcohols including methanol,...

The impact of alkyl chain length on the esterification of C 2 –C 16 organic acids with C 1 –C 4 alcohols has been systematically investigated over bulk and SBA-15 supported sulfated zirconias (SZs). Rates of catalytic esterifica-tion for methanol with acetic acid are directly proportional to the sulfur content for both SZ and SZ/SBA-15, with the hi...

A family of bulk and SBA-15 supported peroxo niobic acid sols were prepared by peptisation of niobic acid precipitates with H2O2 as heterogeneous catalysts for aqueous phase glucose and fructose conversion to 5-hydroxymethylfurfural (5-HMF). Niobic acid nanoparticles possess a high density of Brønsted and Lewis acid sites, conferring good activity...

The grafting and sulfation of zirconia conformal monolayers on SBA-15 to create mesoporous catalysts of tunable solid acid/base character is reported. Conformal zirconia and sulfated zirconia (SZ) materials exhibit both Brönsted and Lewis acidity, with the Brönsted:Lewis acid ratio increasing with film thickness and sulfate content. Grafted zirconi...

A family of tungstated zirconia solid acid catalysts were synthesised via wet impregnation and subsequent thermochemical processing for the transformation of glucose to 5-hydroxymethylfurfural (HMF). Acid strength increased with tungsten loading and calcination temperature, associated with stabilisation of tetragonal zirconia. High tungsten dispers...

Here we describe a simple route to creating conformal sulphated zirconia monolayers throughout an SBA-15 architecture that confers efficient acid-catalysed one-pot conversion of glucose to ethyl levulinate.

The telescopic conversion of glucose to fructose and then 5-hydroxymethylfurfural (5-HMF), the latter a potential, bio-derived platform chemical feedstock, has been explored over a family of bifunctional sulfated zirconia catalysts possessing tuneable acid–base properties. Characterisation by acid–base titration, XPS, XRD and Raman reveal that subm...

A synthesis gas (syngas) with a composition corresponding to that of a biomass gasifier has been reformed over Rh-containing monolith catalysts in the absence and presence of typical undesired species in the syngas. When toluene, a typical light tar component, was added, there was some loss of conversion, probably due to competitive adsorption and...