ZrO2 Catalysts Research Articles

Acetic Acid Production from CH4 and CO2 via Synergistic Catalysis between Pd Particles and Oxygen Vacancies Generated in ZrO2

Co-conversion of CO2 and CH4 into acetic acid is of great significance to the environment but is challenged by their chemical stability. Herein, Pd–ZrO2 catalysts exhibit excellent performance for acetic acid production, which is about 5 times higher than that for pure ZrO2. Combined catalytic tests, characterization, and density functional theory (DFT) calculations have revealed a synergistic catalysis mechanism between Pd and H2-reduced ZrO2, which not only facilitates CO2 adsorption and activation owing to generating more oxygen vacancies (Ov) but also promotes CH4 activation owing to resulting larger-sized metallic Pd particles. DFT calculations demonstrate that the C–C coupling between CH3* and COOH* exhibits a lower barrier, which favors acetic acid formation.

Highly Efficient Au/ZnO−ZrO2 Catalysts for CO Oxidation at Low Temperature

A series of gold catalysts on ZnO−ZrO2 featuring nominal ZnO loads of 3, 5, and 10 wt. % were synthesized by the sol–gel method using Zn(NO3)2 and zirconium (IV) propoxide aqueous solutions. In addition, gold catalysts with nominal loads between 1 and 3 wt. % were produced by the method of deposition-precipitation with urea, and their performance in the CO oxidation reaction at low temperature was evaluated. HRTEM outcomes revealed high gold dispersion on the 3Au/5ZnO−ZrO2 catalyst with Zn/Zr atomic ratio of (5/95) and 3 wt. % of gold, which showed the highest CO conversion at low temperature (−5 °C) under air treatment when the CO oxidation was carried out with a space velocity of ~46,000 h−1. The incorporation of ZnO to ZrO2 provoked high dispersion of the gold nanoparticles on the support and close size distribution; moreover, the presence of Au1+ and Zr3+ species was increased by the Zr−O−Zn interaction, which was stronger than in the single Au/ZrO2 and Au/ZnO catalysts. DRIFT/GC−MS confirmed that the Au1+/Au0 ratio and formation of carbonate species played an important role in determining the CO conversion; likewise, the 3Au/5ZnO–ZrO2 catalyst was stable at 10 °C for 24 h.

Realizing and Revealing Complex Isobutyl Alcohol Production over a Simple Cu–ZrO2 Catalyst

CO hydrogenation to isobutyl alcohol is a promising route for CO transformation to high value-added products. However, the formation mechanism of isobutyl alcohol is complex, and its synthesis requires complex catalysts and harsh reaction conditions, which hinders the identification of active sites. Herein, we efficiently synthesized isobutyl alcohol under mild conditions over a simple Cu–ZrO2 catalyst by decreasing the Cu loading. The space–time yield (STY) of isobutyl alcohol using an optimal CZ-0.11 catalyst was as high as 61.3 g·Lcat–1·h–1 with a CO conversion of 19.2%, far surpassing the STY of the state-of-the-art isobutyl alcohol synthesis (44.6 g·Lcat–1·h–1) under harsh conditions. Decreasing the Cu loading increased the distribution of smaller Cu particles and clarified the structure–activity relationship of Cu–Zr interactions for isobutyl alcohol synthesis. The enhanced Cu–Zr interaction led to the formation of more electron-deficient Cu species on the CZ-0.11 catalyst, which enriched the linearly adsorbed CO on Cu, as demonstrated by in situ diffuse reflectance infrared Fourier-transform spectroscopy. Experimental and theoretical results revealed that coupling of the bicarbonate species on ZrO2 with the linearly adsorbed CO species on electron-deficient Cu clusters promoted the formation of C2 intermediates and finally produced isobutyl alcohol through rapid β-addition. These insights into the active sites for CO hydrogenation to isobutyl alcohol may guide further catalyst designs.

Phosphate-modified Al2O3–ZrO2 supported Ni catalysts for efficient selective methanation of CO in H2-rich reformate gas

CO selective methanation can remove the CO in H2-rich reformate gas to prevent the poisoning of Pt anode electrode in proton exchange membrane fuel cell. However, the methanation of CO2 in H2-rich gas consumes a lot of hydrogen, which greatly reduces the energy efficiency. In order to inhibit CO2 methanation, mesostructured Al2O3–ZrO2 was modified by different amounts of phosphate, and then was as Ni support. The structures and surface properties of Ni/Al2O3–ZrO2 catalyst modified by phosphate were studied to reveal the effect of phosphate-modification on CO conversion and selectivity for CO methanation. It was found that the phosphate-modification inhibited the adsorption of CO2, which increased the selective for CO methanation. But the modification with excess phosphate lessened active sites of Ni and weakened the adsorption of H2 and CO, which decreased the activity of CO methanation.

Green synthesis of spherical mesoporous SBA-16 and its supported Fe2O3- ZrO2 catalyst for selective acetalization of glycerol to dioxolane as biofuel additive

Acid catalyzed acetalization of glycerol to fuel additive is an important valorization for the available surplus glycerol arising due to ever increasing biodiesel production. For this reaction, mesoporous spherical SBA-16 was synthesized first time from bamboo leaf ash derived sodium silicate (BLASS) and impregnated with 10 wt% each of Fe and Zr, characterized by XRD, N2 adsorption-desorption, SEM-EDX, TEM, NH3 TPD, XPS and evaluated for the acetalization of glycerol with furfural. The crystalline and pore structure of SBA-16 (BLASS) support were not altered by the impregnated Fe and Zr which formed α-Fe2O3 and monoclinic ZrO2 respectively on its surface. Fe2O3 and ZrO2 impregnated spherical SBA−16 (BLASS) gave higher glycerol conversion and dioxalane selectivity compared to the same impregnated on shapeless SBA-16, synthesized from tetraethyl orthosilicate (TEOS), confirmed the positive influence of spherical morphology. Further it retained the activity and selectivity for five recycles. Prolonged reaction time transformed kinetically favored dioxolane to thermodynamically stable dioxane based on which plausible reaction mechanism was proposed. Optimum temperature, glycerol: furfural feed molar ratio, amount of catalyst and reaction time were found to be 100 °C, 1:1, 3.6 wt% of glycerol and 3 h respectively for the maximum glycerol conversion with the highest dioxolane selectivity. Glycerol conversion and dioxolane selectivity for acetalization of glycerol with para substituted benzaldehydes were less than benzaldehyde due to steric effect. Dioxalane selectivity decreased with increase in size of aldehydes due to inductive effect while the cyclic ketones were more reactive for the acetalization of glycerol.

Direct ethyl acetate synthesis from ethanol over amorphous-, monoclinic-, tetragonal ZrO2 supported copper catalysts prepared from the same zirconium source

Direct ethyl acetate synthesis from ethanol was examined by supported Cu catalysts on various kinds of acid-base metal oxides, available ZrO2-based oxides, and homemade amorphous-, monoclinic- and tetragonal zirconia prepared from the same Zr source. XRD, XAFS, TG-DTA characterization and surface area measurement were performed. Effects of crystalline phase of ZrO2 support on selective ethyl acetate production was discussed based on the yields and products ratio (ethyl acetate to sum of C4-alcohols and aldehydes). Based on catalytic performance by 29 kinds of homemade catalysts, amorphous-type ZrO2 was found to be essentially the most suitable ZrO2 phase for the selective ethyl acetate formation in cases without any surface modifications. The acid site on the surface of monoclinic-type ZrO2 catalysts possibly promoted unfavorable acetaldehyde condensation reaction, but addition of Na+ for poisoning could increase selectivity of ethyl acetate formation. Coordination environment of Cu species for fresh and spent catalysts were discussed.

A comparative study of zirconia supported nickel and/or ruthenium catalysts for glycerol steam reforming

The physico-chemical properties of Ni, Ru, Ru–Ni monoclinic ZrO2 catalysts were studied and their catalytic activities in the glycerol steam reforming reaction (GSR) were compared. The catalysts were prepared by the wet impregnation method, calcined at 600 °C and characterized using XRD, BET, H2-TPR and CO2-TPD techniques. The XRD analyses revealed varying crystallite sizes depending on the active phase nature and composition. The H2-TPR analyses demonstrated that the reducibility of the active metal oxide species and its dispersion were affected by the active phase composition. The CO2-TPD analyses revealed that surface modification following impregnation modified the basic properties of the catalysts. The catalytic activity tests (T = 400–700 °C, WGFR 9:1, flow rate of 0.025 mL/min) showed that the nickel based catalysts were active while the ruthenium based catalyst was inactive. Combining ruthenium and nickel over zirconia led to smaller Ni particle sizes and a better metal dispersion both of which contributed to higher H2 yields and an increased coke resistance. During 24 h on stream, the combined Ru–Ni/ZrO2 catalyst maintained a higher total glycerol conversion compared to the Ni/ZrO2 catalyst. Only filamentous coke was identified on the spent catalysts after the stability tests. For a higher water to glycerol feed ratio (WGFR 46:1), encapsulating coke was formed over Ru–Ni/ZrO2 leading to the blockage of active sites and a more rapid catalyst deactivation.

Facile synthesis of zirconia supported nanomaterials for efficient photocatalytic applications

AbstractThe recent study enlightens the synthesis and characterization of zirconia (ZrO2), Fe‐doped ZrO2 (Fe@ZrO2), and Ni‐doped ZrO2 (Ni@ZrO2) catalysts having new‐fangled morphology with tuned band gap as photocatalysts for degradation of textile wastewater dyes methylene blue (MB), malachite green (MG), and their mixtures. SEM imaging of Fe@ZrO2 and Ni@ZrO2 is interestingly varied from ZrO2 as well as doping of transition metals greatly affects the morphology of composites. The optimization study depicts that the pH, time (min) and catalyst amount (g) have a direct relation with degradation efficiency, while the dye concentration (mg/L) has an indirect relation as well. The photocatalytic studies depict that the degradation of MB and MG follows oxidation pathway via hydroxyl radicals (OH•) and holes. Reusability of catalysts corresponds to a little decrease in degradation efficiency in the first two cycles and decreases to about ∼10% (Ni@ZrO2) and ∼12% (Fe@ZrO2) in next three cycles.

Advancing nitrate reduction to ammonia: insights into mechanism, activity control, and catalyst design over Pt nanoparticle-based ZrO2.

The reduction of nitrogen oxides (NOx) to NH3, or N2 represents a crucial step in mitigating atmospheric NO3 and NO2 emissions, a significant contributor to air pollution. Among these reduction products, ammonia (NH3) holds particular significance due to its utility in nitrogen-based fertilizers and its versatile applications in various industrial processes. Platinum-based catalysts have exhibited promise in enhancing the rate and selectivity of these reduction reactions. In this study, we employ density functional theory (DFT) calculations to explore the catalytic potential of Pt nanoparticle (PtNP)-supported ZrO2 for the conversion of NO3 to NH3. The most favorable pathway for the NO3 reduction to NH3 follows a sequence, that is, NO3 → NO2 → NO → ONH → ONH2/HNOH → NH2/NH → NH2 → NH3, culminating in the production of valuable ammonia. The introduction of low-state Fe and Co dopants into the ZrO2 support reduces energy barriers for the most challenging rate-determining hydrogenation step in NOx reduction to NH3, demonstrating significant improvements in catalytic activity. The incorporation of dopants into the ZrO2 support results in a depletion of electron density within the Pt cocatalyst resulting in enhanced hydrogen transfer efficiency during the hydrogenation process. This study aims to provide insights into the catalytic activity of platinum-based ZrO2 catalysts and will help design new high-performance catalysts for the reduction of atmospheric pollutants and for energy applications.

Selective Hydrodeoxygenation of Glycerol to 1,2-Propanediol with the Pt/CeO2–ZrO2 Catalyst

Selective Hydrodeoxygenation of Glycerol to 1,2-Propanediol with the Pt/CeO2–ZrO2 Catalyst

Highly Active Bimetallic Single-Atom Alloy PdAg Catalysts on Cerium-Containing Supports in the Hydrogenation of Alkynes to Alkenes

A study of a series of single-atom-alloy catalysts Pd1Ag3/Al2O3, Pd1Ag3/CeO2–Al2O3, and Pd1Ag3/CeO2–ZrO2 in the selective hydrogenation of diphenylacetylene (DPA) showed a significant (five-fold) increase in activity for the PdAg3/CeO2–ZrO2 sample in comparison with that of Pd1Ag3/Al2O3. It was especially noted that the increase in activity was not accompanied by a decrease in the selectivity for the target product. This catalytic behavior can be explained by two factors: (1) a more than twofold increase in the dispersity of the PdAg3/CeO2–ZrO2 catalyst and (2) a change in the electronic state of the nanoparticles, as determined from the results of an IR-spectroscopic study of adsorbed CO. The retention of the high selectivity of the synthesized catalysts indicated the stability of the structure of Pd1 monoatomic sites in the catalysts prepared by deposition on Ce-containing supports, which was also confirmed by the IR spectroscopy of adsorbed CO. The experimental results indicate that Ce-containing supports are promising for the synthesis of catalysts for the selective hydrogenation of substituted alkynes.

Ni-catalyzed CO2 glycerol reforming to syngas: New insights on the evaluation of reaction and catalyst performance

Glycerol dry reforming (GDR) to syngas was studied on Ni/ZrO2, Ni/La2O3 and Ni/La2O3–ZrO2 catalysts for elucidating the effects of support material on catalyst performance. A methodology was proposed to quantify the produced H2O, which was not reported so far in the GDR literature. At 750 °C, molar inlet CO2–to–glycerol vapor ratio (CO2/G) of 1–3 and residence time of 0.25 mgcat.min/Nml, the average CO2 and glycerol conversions were ordered as 13 % (NiLZ) > 10 % (NiZ) > 9 % (NiL) and 93 % (NiLZ) > 89 % (NiZ) > 83 % (NiL), respectively. NiLZ, the most active catalyst, also delivered > 95 % of the pertinent thermodynamic CO2 conversion at 0.5 mgcat.min/Nml. The 24 h stability of NiL and NiZ catalysts depended strongly on the inlet CO2 concentration. At CO2/G = 2, NiL deactivated by ∼5 % which was doubled at CO2/G = 4 mainly due to coking shown by TGA and Raman spectroscopy. The catalyst also suffered from Ni agglomeration as revealed by SEM–EDX and XRD. NiZ catalyst lost ∼21 and ∼9 % of its initial activity after 24 h aging at CO2/G = 2 and 4, respectively. Despite insignificant coking and sintering, XPS analyses pointed out almost four–fold decrease in the surface atomic Ni concentration on NiZ at CO2/G = 2 and suggested partial blockage of Ni sites by increased reducibility of monoclinic ZrO2 support at the less oxidative, CO2–lean environment. Regardless of the atmosphere, the NiLZ catalyst showed excellent stability features comparable to those of the notably higher–priced Rh and Ru–containing counterparts.

Novel mesoporous submicron SO42−/FeCu-ZrO2 catalyst for highly selective liquid-phase nitration of 1-nitronaphthalene with NO2 to 1, 5-dinitronaphthalene under mild conditions

An efficient approach for highly selective preparation of 1,5-dinitronaphthalene from liquid-phase nitration of 1-nitronaphthalene with NO2 over mesoporous submicron sub-SO42−/Fe1.5Cu0.5-ZrO2 (s-SFCZ) superacid catalyst prepared by the two-step hydrothermal impregnation (THI) method has been developed. The results showed that the enhanced 1-nitronaphthalene conversion and 1,5-dinitronaphthalene selectivity were attributed to the synergistic catalysis of s-SFCZ combined O2-Ac2O. 94.8% of 1-nitronaphthalene conversion and 62.1% 1,5-dinitronaphthalene selectivity were achieved under optimal conditions. The characterization results unveiled that s-SFCZ had a uniform morphology, lower nano-crystallite size along with more number of accessible acid sites as compared to SO42−/Fe1.5Cu0.5-ZrO2 (SFCZ) and SO42−/Fe1.5Cu0.5/ZrO2 (SFC/Z) catalysts prepared by conventional methods. Furthermore, the density functional theory calculation revealed the cause of the favorable selectivity to 1,5-dinitronaphthalene in NO2-O2-Ac2O compares to HNO3 system. This work affords a novel strategy for preparing mesoporous submicron catalyst used in the nitration of 1-nitronaphthalene with NO2 to 1,5-dinitronaphthalene, and has potential application prospects.

Alkylation for removing trace olefins from reforming aromatics over novel Al2O3@SO42-/ZrO2 catalysts derived from the ZrO2-coated γ-Al2O3 strategy

Sulfated zirconia, as a promising catalyst in various acid-catalytic reactions, still suffer from unsatisfactory catalytic stability and regeneration performance due to severe leaching of sulfur species, while aluminum modification can effectively overcome these drawbacks. Unfortunately, the limited acceptability of aluminum content by co-precipitation and milling methods remains a critical issue. Herein, an effective strategy of coating sulfated zirconia on the surface of γ-Al2O3 was developed to synthesize the novel Al2O3@SO42-/ZrO2 catalyst with high aluminum content. The synthesis variables were investigated and systematically optimized. The structural and acidic properties of Al2O3@SO42-/ZrO2 were determined by XRD, HR-TEM equipped with EDX, N2 adsorption-desorption isotherms, EA, FT-IR, NH3-TPD and Py-FTIR. Results indicated that the unique structure constructed by sulfated zirconia coated on γ-Al2O3 not only realized the stabilization of favorable tetragonal zirconia phase even at exceedingly high aluminum content but also promoted Brønsted acid sites. Accordingly, the optimal Al2O3@SO42-/ZrO2-50% performed outstanding catalytic activity and stability, given the olefins conversion of 98%-75% during the continuous reaction experiment. Owing to the alleviation of sulfur loss by Al-promoting effects, excellent regeneration performance, with olefins conversion only slightly declining after 4 consecutive reaction-regeneration cycles, was also obtained. The mechanistic pathway for the alkylation of olefins with aromatics over Al2O3@SO42-/ZrO2 was also investigated and proposed by GC–MS analysis.

Hybrid MOF Template-Directed Construction of Hollow-Structured In2 O3 @ZrO2 Heterostructure for Enhancing Hydrogenation of CO2 to Methanol.

Direct hydrogenation of CO2 to methanol using green hydrogen has emerged as a promising method for carbon neutrality, but qualifying catalysts represent a grand challenge. In2 O3 /ZrO2 catalyst has been extensively applied in methanol synthesis due to its superior activity; however, the electronic effect by strong oxides-support interactions between In2 O3 and ZrO2 at the In2 O3 /ZrO2 interface is poorly understood. In this work, abundant In2 O3 /ZrO2 heterointerfaces are engineered in a hollow-structured In2 O3 @ZrO2 heterostructure through a facile pyrolysis of a hybrid metal-organic framework precursor MIL-68@UiO-66. Owing to well-defined In2 O3 /ZrO2 heterointerfaces, the resultant In2 O3 @ZrO2 exhibits superior activity and stability toward CO2 hydrogenation to methanol, which can afford a high methanol selectivity of 84.6% at a conversion of 10.4% at 290°C, and 3.0MPa with a methanol space-time yield of up to 0.29gMeOH gcat -1 h-1 . Extensive characterization demonstrates that there is a strong correlation between the strong electronic In2 O3 -ZrO2 interaction and catalytic selectivity. At In2 O3 /ZrO2 heterointerfaces, the electron tends to transfer from ZrO2 to In2 O3 surface, which facilitates H2 dissociation and the hydrogenation of formate (HCOO*) andmethoxy (CH3 O*) species to methanol. This study provides an insight into the In2 O3 -based catalysts and offers appealing opportunities for developing heterostructured CO2 hydrogenation catalysts with excellent activity.

A solar photothermo-catalytic combined process for the VOCs combustion and the subsequent CO2 valorization using noble metal-free catalysts

We here investigated a solar photothermo-catalytic combined process where the toluene (as volatile organic compound model) was first oxidized to CO2 which was subsequently converted into solar fuels in a second reactor. For this aim two noble-metal free catalytic systems were used, namely MnOx-ZrO2, which gave the best results for the toluene removal, and brookite TiO2-CeO2 mixed oxides which were the most efficient in the subsequent CO2 conversion. This latter reaction was further improved by the addition of small amounts of copper-based materials on brookite-ceria, acting as co-catalysts. The key point for both the examined reactions was the synergism between the thermocatalytic and the photocatalytic mechanisms that enhanced the energy saving and the catalytic performance. In particular, with the MnOx-5 wt%ZrO2 catalyst 90 % of toluene was converted into CO2 at 180 °C (gas hourly space velocity (GHSV) 3.9 × 10−3 moltoluene h−1 gcat-1), about 50 °C less than in the bare thermocatalytic tests and the obtained CO2 was converted into CO (17.6 µmol/gcat∙h) and CH4 (7.9 µmol/gcat∙h) with the CuOx/TiO2-3 %wt CeO2 sample at 120 °C. The photothermo-catalytic activity was about 4 times higher than solar photocatalytic activity and greater than the thermocatalytic one that required a temperature above the 200 °C. The proposed approach is promising to obtain solar fuels starting from toxic pollutants.

Carbon Formation during Methane Dry Reforming over Ni-Containing Ceria-Zirconia Catalysts.

Two series of Ni/Ce(Ti/Nb)ZrO2 catalysts were prepared using citrate route and original solvothermal continuous flow synthesis in supercritical isopropanol and studied in dry reforming of methane (DRM). TEM, XPS and FTIRS of adsorbed CO confirm influence of support composition and preparation method on the catalysts’ morphology and surface features. The oxygen mobility was studied by isotope heteroexchange with C18O2. After testing in DRM, carbon deposits after catalysts’ testing in DRM were investigated by temperature-programmed oxidation with thermo-gravimetric analysis. The lowest amounts of carbon deposits were obtained for unmodified Ni-CeZr and Ni-CeNbZr compositions. Ti addition lead to an increased amount of carbon, which was removed at higher temperatures. The use of supercritical supports also resulted in the formation of a higher amount of coke. Catalysts prepared by the supercritical synthesis were tested in DRM for 25 h. The highest activity drop was observed in the first three hours. For all compositions, close values of carbon deposits were revealed.

Dual experimental and computational approach to elucidate the effect of Ga on Cu/CeO2–ZrO2 catalyst for CO2 hydrogenation

Cu–Ga catalysts are potential candidates for activating the selective and stable hydrogenation of carbon dioxide to methanol and dimethyl ether. This work explores the structure–function relationship in specific Cu–Ga/CeO2–ZrO2 catalysts with different Ga loadings. Combining experiments with density functional theory calculations, we find the most well-balanced Cu–Ga interphase (structure) and promote specific mechanistic pathways of the reaction (function). The experiments yielded the highest selectivity of the desired products when the Cu and Ga amounts were equal. The experimental work and density functional theory calculations demonstrated that methanol is formed through the carboxyl pathway on the Cu catalyst, while Ga promotes the formate pathway. Consequently, the productivities of both methanol and dimethyl ether are enhanced. The experimental results match well with the theoretical calculations. Comparing our results with other Ga-promoting systems, we also prove that Cu achieves better balance than Ni and Co.

The effect of the change of the structure on oxidative dehydrogenation of propane over cerium–zirconium catalysts

AbstractA series of pure CeO2, ZrO2, and CeZrOx mixed metal oxide catalysts were prepared by a wetness impregnation method and were applied to the dehydrogenation of propane to propylene at 500°C and 0.1 MPa. The prepared catalysts were characterized by thermal gravimetric analysis (TGA), Brunauer, Emmett, and Teller (BET), X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopes (TEM), Raman spectroscopy, and H2‐TPR. It was observed that the zirconium content of the solid solution of the mixed metal oxide catalyst was 5%–25%, while the zirconium content of the material with phase segregation was higher (50%). The addition of zirconium was proven to decrease the oxygen vacancy concentration on the catalyst surface and change the intensity of (111) crystal of cerium oxide in the catalysts. Among the prepared catalysts, the Ce0.90Zr0.10Ox catalyst with the maximum strength of the (111) crystal plane of cerium oxide exhibited the better catalytic oxidation performance for the dehydrogenation of propane to propylene. Compared with ZrO2 in the blank experiment, the average propane conversion and propylene selectivity of the Ce0.90Zr0.10Ox catalyst were increased by 10.78% and 17.95%, respectively.

Production of green jet fuel from furanics via hydroxyalkylation-alkylation over mesoporous MoO3-ZrO2 and hydrodeoxygenation over Co/γ-Al2O3: Role of calcination temperature and MoO3 content in MoO3-ZrO2

Green biofuels are equivalent to hydrocarbon-based motor fuels and compatible with existing refinery infrastructures and combustion engines. Therefore, sustainable production of green biofuels is essential to circumvent the construction of expensive biorefinery infrastructures. This study thus presents the production of green jet fuel from biomass-derived furanic compounds via hydroxyalkylation-alkylation (HAA) reaction coupled with hydrodeoxygenation (HDO) of the C15 biofuel precursor. MoO3-promoted ZrO2 is a promising solid acid catalyst with excellent thermal stability. The HAA reaction of 2-methylfuran with furfural was thus investigated over a novel MoO3-promoted mesoporous ZrO2 catalyst. This work elucidated the role of calcination temperature and MoO3 loading on the structural variation of MoO3-promoted mesoporous ZrO2 and the evolution of acid sites. The highest acid density and consequently best catalytic performance was observed at 873 K calcination temperature with 20 wt% MoO3 loading. About 85 % 2-methylfuran conversion was achieved over 1.25 g of this optimum catalyst at 2:1 2-methylfuran/furfural mole ratio, 323 K, and 5 h. The HAA reaction was further investigated at various reaction temperatures, catalyst loadings, and 2-methylfuran/furfural mole ratios to obtain optimum reaction conditions. HDO of biofuel precursor was examined over Co/γ-Al2O3 catalyst at various reaction temperatures, initial hydrogen pressure, and Co metal loading on γ-Al2O3 to understand the reaction mechanism and identify the optimum reaction conditions. HDO of biofuel precursor progressed through successive furan ring saturation and opening reactions, followed by a combination of HDO, decarbonylation, and cleavage of tertiary-carbon bonds. C9-C15 alkanes were observed as products, with C11 and C14 hydrocarbons being dominant at 573 K and 30 bar. The elevated hydrogen pressure and reaction temperature boosted the conversion of oxygen-containing intermediate compounds at the cost of CC cracking reactions. The conversion of oxygen-containing intermediate compounds was enhanced with rising Co metal loading on γ-Al2O3 up to 20 wt% due to the enhancement of metal dispersion.