NH3 Temperature-programmed Desorption Research Articles

An Unusually Acidic and Thermally Stable Cesium Titanate Cs xTi2- yM yO4 ( x = 0.67 or 0.70; M = vacancy or Zn).

Proton-free, alkali-containing layered metal oxides are thermally stable compared to their protonic counterparts, potentially allowing catalysis by Lewis acid sites at elevated temperatures. However, the Lewis acidic nature of these materials has not been well explored, as alkali ions are generally considered to promote basic but to suppress acidic character. Here, we report a rare example of an unusually acidic cesium-containing oxide Cs xTi2- yM yO4 ( x = 0.67 or 0.70; M = Ti vacancy □ or Zn). These lepidocrocite-type microcrystals desorbed NH3 at >400 °C with a total acidity of ≲410 μmol g-1 at a specific surface area of only 5 m2 g-1, without the need for lengthy proton-ion exchange, pillaring, delamination, or restacking. The soft and easily polarized Cs+ ion essentially drives the formation of the Lewis acidic site on the surfaces as suggested by IR of sorbed pyridine. The two-dimensional layered structure was preserved after the oxide was employed in the ethanol conversion at 380 °C, the temperature at which the protonic form could have converted to anatase. The structure was also retained after the NH3 temperature-programmed desorption measurement up to 700 °C. The production of ethylene from ethanol, well-known to occur over acid sites, unambiguously confirmed the acidic nature of this cesium titanate.

N-Dodecane Hydroisomerization over Hierarchical ZSM-22 Prepared by a Dual-Protected Alkali Treatment

In this work, a series of hierarchical ZSM-22 zeolites are prepared by a dual-protected alkali treatment route in the presence of microporous and mesoporous templates. The pore structure and acidity of hierarchical ZSM-22 zeolites are tailored by partial detemplation and addition of cetyltrimethylammonium bromide (CTAB), which are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma, N2 adsorption–desorption, temperature-programmed desorption of NH3, Py-IR, Lu-IR, and 27Al magic-angle spinning nuclear magnetic resonance. The retained microporous templates after partial detemplation keep the ZSM-22 rod-like morphology in the alkali treatment. CTAB effectively introduces uniform mesoporosity centered at ca. 3.2 nm. As a result, as-prepared hierarchical ZSM-22 (430ATC) contains a large amount of small mesopores and pore-mouths, and higher desilication efficiency is achieved. After loading 0.5 wt % Pt, this hierarchical ZSM-22 supported...

Poisoning effects of lead species on the V2O5‐WO3/TiO2 type NH3‐selective catalytic reduction catalyst

AbstractHeavy metal Pb is an inevitable ingredient of coal‐fired flue gas and has been proven to be a source of inhibiting effect on the selective catalytic reduction (SCR) catalyst. In this paper, two types of Pb‐poisoned catalyst, prepared by the incipient wetness impregnation and solid diffusion methods, are studied to unveil the poisoning effects of lead species on the V2O5‐WO3/TiO2 catalyst. The activity test results showed that lead species loaded by the incipient wetness impregnation method exhibited a significant inhibiting effect on the denitrification efficiency of the catalyst although a negligible activity loss was observed on the samples from the solid diffusion method. Characterizations of fresh and Pb‐poisoned catalysts from incipient wetness impregnation method were applied using comprehensive techniques such as X‐Ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), X‐ray fluorescence (XRF), NH3‐temperature programmed desorption (NH3‐TPD), X‐Ray photoelectron spectroscopy (XPS), and so forth. The analytical results indicated that a phase transformation occurred in tungsten species and the amorphous WO3 converted into PbWO4, causing the accumulation and valence imbalance of active vanadium phase, which further decreased the surface acidity and activity of the V2O5‐WO3/TiO2 catalyst.

Simultaneous removal of NOx and Hg0 from simulated flue gas over CuaCebZrcO3/r-Al2O3 catalysts at low temperatures: performance, characterization, and mechanism.

To optimize the simultaneous removal of NOx and Hg0, a series of CuaCebZrcO3/γ-Al2O3 catalysts prepared by the impregnation method were explored and their physical and chemical properties were analyzed by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, X-ray photoelectron spectroscopy (XPS), NH3-temperature-programmed desorption (NH3-TPD), H2-temperature-programmed reduction (H2-TPR), in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFT), and Fourier transform infrared spectroscopy (FT-IR). The results showed that 15% Cu1.4Ce0.55Zr0.25O3/γ-Al2O3 resulted in the highest conversion efficiency for the simultaneous removal of NOx (93%) and Hg0 (85%) at low temperatures (200 to 300°C). Meanwhile, 15% Cu1.4Ce0.55Zr0.25O3/γ-Al2O3 showed good stability and resistance to SO2 and H2O, which is due to its low crystallinity, good textural performance, and strong redox ability. According to the TPD, TPR, and XPS results, the strong acidic character of 15% Cu1.4Ce0.55Zr0.25O3/γ-Al2O3 promoted the removal of NOx and Hg0. The synergistic effect between CuO and CeO2 in 15% Cu1.4Ce0.55Zr0.25O3/γ-Al2O3 can increase the mobility of chemically adsorbed oxygen and activates lattice oxygen, leading to an excellent performance. The DRIFT results showed that NH3, NH4+, nitrate, and nitrite participated in the selective catalytic reduction (SCR) reaction. On the basis of our experimental results, Hg0 and NOx removal mechanisms were proposed as Hg (ad) + O* → HgO (ad) and 2NH3/NH4+ (ad) + NO2/NO3- (ad) + NO→2N2 + 3H2O/2H+, respectively.

Direct catalytic decomposition of N2O over Co(x)/RPSA catalysts

As one of the main greenhouse gases, reducing emissions of N2O is imperative, for which catalytic decomposition is one of the most effective methods. A series of cobalt catalysts supported on RPSA zeolite, denoted as Co(x)/RPSA-T, were prepared using the impregnation method and characterized by X-ray diffraction (XRD) analysis, Brunauer–Emmett–Teller (BET) measurements, thermogravimetric mass spectrometry (TG–MS), H2 temperature-programmed reduction (TPR), NH3 temperature-programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence (XRF) spectroscopy, and in situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS). Catalytic activity tests for N2O decomposition were carried out in a fixed-bed microreactor. The results showed that the redox properties of the catalysts remarkably influenced their catalytic performance. The catalytic activity results for the Co(10)/RPSA-600 catalyst showed the best performance under the conditions of 0.65 vol% N2O, 0.88 vol% O2, with Ar as balance gas, achieving conversions of 10 % and 90 % of N2O at temperature of 348 °C and 438 °C, respectively.

Spatial Confinement Effects of Microcapsule Catalyst for Improved Coking‐ and Sintering‐Resistant Behaviors Toward CO2 Reforming of Methane Reaction

The CO2 dry reforming of methane (DRM) reaction is an important technology with high prospects to reduce greenhouse gas emissions while simultaneously producing syngas for industrial usage. To date, the lack of an effective catalyst for the reaction has inhibited its commercialization. The coking and sintering behaviors of the catalysts are key factors for commercial production of syngas from DRM reaction. A microcapsule catalyst prepared by sol–gel method with Ni/ZSM‐5 as core and amorphous SiO2 as shell is successfully synthesized. The characterizations of the catalysts are analyzed using X‐ray powder diffraction (XRD), transmission electron microscopy (TEM), H2 temperature programmed reduction (H2‐TPR), NH3 temperature programmed desorption (NH3‐TPD), and thermogravimetry & differential scanning calorimetry (TGA‐DSC). The spatial confinement of the Ni metal particles between the SiO2 shell and ZSM‐5 suppresses Ni particles aggregation by strengthening the interaction between Ni particles and ZSM‐5 core. The coking‐resistant ability is equally improved. The capsule catalysts isolate the contact between the carbon deposits and the nickel active centre, thus improving the activity of the catalysts. 10Ni/ZSM‐5@SiO2 emerged superior in activity in comparison to other catalysts.

Synthesis of solketal over zirconia based acid catalysts

Microwave assisted synthesis of ‘solketal’ over zirconia (ZrO2) and its modified forms (Mo(VI)/ZrO2, W(VI)/ZrO2 and V(V)/ZrO2) coated on honeycomb monoliths is reported. The solid acids were coated on honeycomb monoliths by ‘dip and dry’ method and characterized for their surface acidity, crystalinity, functionality, morphology and elemental analysis by using techniques such as NH3-Temperature programmed desorption (NH3-TPD), powder X-ray diffraction (PXRD), Fourier transform-infrared spectroscopy (FTIR), Scanning electron microscopy (SEM) and Inductively coupled plasma-optical emission spectroscopy (ICP-OES). The honeycomb monoliths coated with solid acids were employed as catalysts in the condensation of glycerol with acetone to synthesize solketal under microwave irradiation conditions. The reaction conditions such as molar ratio of the reactants (glycerol: acetone), reaction temperature, reaction time were studied to obtain highest possible yield of solketal with greater selectivity. The catalytic activity of honeycomb catalytic material was compared with the powder forms of the catalysts. 98% yield of solketal with 98% selectivity was achieved over Mo(VI)/ZrO2 coated on a honeycomb monolith in a very shorter reaction time of 8 min at 60 oC under microwave heating. These honeycomb catalytic material were found to be easily reactivable and reusable atleast for 6 reaction cycles. Hence, honeycomb catalysts were found to be efficient, economical and effective in the synthesis of value added chemical such as solketal. A possible mechanism for the formation of solketal is proposed.
 Bangladesh J. Sci. Ind. Res.54(1), 31-38, 2019

The role of molybdenum on the enhanced performance and SO2 resistance of V/Mo-Ti catalysts for NH3-SCR

The influence of molybdenum on the selective catalytic reduction (SCR) performance and SO2 durability of V/Mo-Ti catalysts was investigated. The characteristics of the catalysts were investigated by Brunauer-Emmett-Teller (BET) surface area analysis, field-emission transmission electron microscopy (FE-TEM), Raman spectroscopy, NH3-temperature programmed desorption (NH3-TPD), in-situ diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTs), SO2 temperature-programmed desorption (SO2-TPD), and X-ray photoelectron spectroscopy (XPS). The V/Mo-Ti catalysts exhibited improved SCR performances and SO2 resistances at 250 °C compared to those of V/W/Ti catalysts. The improved catalytic activity was shown to be imparted by amorphous MoOx. The formation of amorphous MoOx species with the addition of molybdenum to titanic acid was found to be more significant than that by the addition of molybdenum to crystalline TiO2. The increased density of NH3-adsorption and Brønsted-acid sites by addition of molybdenum was found to have a positive effect on catalyst performance. Since the reaction between SO2 and VOx was suppressed by the addition of molybdenum, the area of the SO2-TPD peak due to desorption of adsorbed SO2 from the catalyst surface was reduced. This decrease in the amount of adsorbed SO2 improved the SO2 resistances of the catalysts. The V/Mo-Ti catalysts exhibited increasing activities and SO2 resistances with increasing Mo6+ ratio (and Mo6+ atoms/cm3). Furthermore, they exhibited suppressed formation of ammonium sulfate salts due to decreased SO2 adsorption, as the reaction of terminal VO groups and adsorbed SO2 is inhibited by the addition of molybdenum. Thus, the V/Mo-Ti catalysts exhibited better catalytic activities and SO2 durability than those of V/W/Ti catalysts.

Effect of preferential exposure of anatase TiO2 {0 0 1} facets on the performance of Mn-Ce/TiO2 catalysts for low-temperature selective catalytic reduction of NOx with NH3

Titanium dioxide with preferentially exposed {001} facets (TiO2-NS) was synthesized by hydrothermal method using HF as a crystal plane regulator. The obtained TiO2-NS was used as the carrier of the low temperature SCR catalysts Mn-Ce/TiO2-NS which was prepared by impregnation method. Meanwhile, Mn-Ce/TiO2-NP catalyst was prepared as a comparison by the same method using titanium dioxide with priority to {101} facets (TiO2-NP) as the carrier. The effect of preferential exposure of anatase TiO2 {001} facets on the low-temperature selective catalytic reduction performance of Mn-Ce/TiO2 was studied. The support TiO2 (TiO2-NS and TiO2-NP) and the SCR catalysts were characterized by means of Scanning electron microscopy (SEM), Transmission electron microscope (TEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface measurement, X-ray photoelectron spectroscopy (XPS), Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and NH3-temperature programmed desorption (NH3-TPD). The results showed that the preferentially exposed {001} facets of TiO2 could increase the specific surface area and the concentration of surface adsorbed oxygen of the catalyst, and enhance the surface acidity. The denitration test indicated that Mn-Ce/TiO2-NS catalyst showed excellent NO conversion. In particular, the catalytic efficiency of Mn-Ce/TiO2-NS was about 30% higher than that of Mn-Ce/TiO2-NP in the low temperature window within 100–160 °C.

Dealumination and desilication for Al-rich HZSM-5 zeolite via steam-alkaline treatment and its application in methanol aromatization

The hierarchical HZSM-5 was prepared via dealumination and desilication of commercial Al-rich HZSM-5, and characterized by X-ray diffraction, 27Al magic-angle spinning nuclear magnetic resonance, inductively coupled plasma mass spectrometry, scanning electron microscope, transmission electron microscope, N2 adsorption-desorption, NH3 temperature-programmed desorption, performed thermogravimetric and Raman spectrum. The results showed that partial framework of HZSM-5 was removed after steam treatment at 0.15 MPa, 500°C for 3 h. HZSM-5 with high specific surface area and much mesoporosity was obtained by the subsequent alkaline treatment. The regulation of acid quantity was achieved by altering the concentration of alkaline. Dealumination and desilication of Al-rich HZSM-5 zeolites became more effective using a combination of steam and alkaline treatments than using alkaline treatment alone. Methanol aromatization reaction was employed to evaluate the catalytic performance of treated HZSM-5 at 0.15 MPa, 450°C and MHSV of 1.5 h–1. The results indicated that after steam treatment, HZSM-5 further treated with 0.2 mol/L NaOH exhibits the best catalytic performance: the selectivity of aromatics reached 42.1% and the lifetime of catalyst attained 212 h, which are much better than untreated HZSM-5.

Designing a hierarchical nanosheet ZSM-35 zeolite to realize more efficient ethanol synthesis from dimethyl ether and syngas

Abstract In this work, a dual-catalyst bed reactor packed with the combination of hierarchical nanosheet HZSM-35 (Hi-NZ35) zeolite and CuZnAl catalyst was proposed to realize more efficient ethanol synthesis from dimethyl ether (DME) and syngas (CO+H2). The nanosheet ZSM-35 (NZ35) zeolite was prepared via a direct hydrothermal synthesis route and the CuZnAl catalyst was prepared by co-precipitation method. Moreover, a series of Hi-NZ35x zeolites were obtained from NZ35 zeolite by further treatment with varied NaOH aqueous solution using hydrothermal process (“x” means the NaOH solution concentration of 0.2-0.6 M). The catalysts properties, such as crystallinity, porosity, acidity, morphology and composition, were characterized by X-ray diffraction (XRD), N2 adsorption-desorption, NH3 temperature-programmed desorption (NH3-TPD), H2 temperature-programmed reduction (H2-TPR), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). It was found that Hi-NZ350.4 zeolite was more effective to obtain hierarchical porosity with mesopore volume up to 0.131 cm3 g−1. For single DME carbonylation reaction, the NZ35 zeolite exhibited superior catalytic activity (32.2%) and stability compared with conventional ZSM-35 (CZ35) zeolite. Furthermore, improved catalytic activity (42.0%) was observed on Hi-NZ350.4 zeolite owing to its abundant mesoporous structure. This result revealed that the hierarchical porosity of zeolite could effectively promote the catalytic performance of zeolite for DME carbonylation reaction. For the ethanol synthesis using the optimized catalysts combination of Hi-NZ350.4 zeolite and CuZnAl catalyst, the DME conversion was about 47.2% with higher ethanol productivity of 840.2 mmol kg−1 h−1.

Effect of acidity of oxide support on the activity and stability of μ-nitrido diiron phthalocyanine complex

Various oxides, including Al2O3, Fe2O3, SiO2, and ZrO2, were employed as catalyst supports for the oxidation of cyclohexane by a μ-nitrido-bis[tetra(tert-butyl)phthalocyaninatoiron] complex. These oxide supports were characterized by Brunauer–Emmett–Teller surface area measurements and NH3 temperature-programmed desorption analyses. The catalyst supported on Al2O3, which has the highest acidity among the oxides considered here, showed the best activity with a turnover number (TON) of ˜108.8, without any co-catalyst. Furthermore, recycle tests of the catalysts revealed a TON of 69.3 for the Al2O3-supported catalyst after the third run. The strongly acidic sites in the Al2O3 support could be responsible for the strong adsorption of μ-nitrido diiron phthalocyanine, resulting in enhanced catalytic activity and stability.

Rapid green synthesis of ZSM-5 zeolite from leached illite clay

Abstract A seed-induced rapid synthesis of submicron ZSM-5 zeolites from acid-leached illite clay was achieved via solid-like state conversion. The optimal synthesis conditions and crystallization mechanism were investigated. The synthesized ZSM-5 zeolites were characterized using X-ray diffraction, scanning electron microscopy, N2 adsorption–desorption, X-ray fluorescence, NH3 temperature-programmed desorption, and 27Al MAS NMR. The results clearly indicated that well-dispersed submicron-size ZSM-5 zeolites were synthesized in the relatively short period of 6 h. In the solid-like state conversion synthesis system induced by crystal seeds, the sample gradually transformed from amorphous to well-dispersed submicron ZSM-5 as the crystallization time increased. Aluminum entered the ZSM-5 zeolites framework to provide acidic sites. The obtained ZSM-5 zeolites showed slightly better catalytic performance in toluene disproportionation than ZSM-5 seeds.

Synthesis of Mo-MCM-48 and their isomerization performances of n-heptane

A series of Mo-MCM-48 molecular sieves were prepared by in-situ doping method and used as the catalyst for isomerization of n-heptane. The samples were characterized by X-ray powder diffraction, scanning electron microscope, transmission electron microscope, Nitrogen adsorption desorption isotherms (N2 adsorption–desorption), NH3 temperature programmed desorption (NH3-TPD), and Fourier Transform infrared spectroscopy (FT-IR). The results showed that Mo-MCM-48 samples modified by Mo species still had the typical cubic mesoporous structure of MCM-48. The results of n-heptane isomerization showed that when the doping amount of Mo species was 0.02, the reaction temperature was 250 °C, and the reaction time was 150 min, the conversion of n-heptane and the selectivity of isoheptane of Mo-MCM-48 were up to 36.71% and 52.41%, respectively. There were no obvious decline of the catalytic activity of Mo-MCM-48 after reaction for 190 min.

Promotion effect of S and N co-addition on the catalytic performance of V2O5/TiO2 for NH3-SCR of NOX

The influence of S and N in the V2O5/TiO2 catalyst system on the activity was evaluated for the selective catalytic reduction (SCR) of NOX. The VTi1 (S/N/Ti = 3:1:100) with wide temperature window has the highest catalytic activity. The properties of the catalysts were characterized by physicochemical measurements, including X-ray diffraction, BET surface area, NH3 temperature-programmed desorption, H2 temperature-programmed reduction and O2 temperature-programmed desorption, and so on. The structure, surface area, Lewis acidity, reducibility and active sites of the catalyst were significantly influenced by adding S and N. The results of ultraviolet–visible spectroscopy and electron paramagnetic resonance indicated that the presence of the strong electron interactions between dispersed vanadia and TiO2 species and more active oxygen species on the surface of catalyst. This work provides new insights into the effect of active oxygen species on the catalytic conversion of the nitrogen oxides.

Catalytic hydrodeoxygenation of jojoba oil to the green-fuel application on Ni-MoS/Mesoporous zirconia-silica catalysts

Zirconia modified mesoporous silica such as Zr-SBA-15, Zr-KIT-6, Zr-SiO2, and Zr-FSM-16 with Si/Zr = 10 ratio over Ni-MoS catalysts were prepared under the hydrothermal condition and compared with Ni-MoS/Zr-Al (10). The prepared materials were characterized by various techniques like X-ray diffraction analysis (XRD), N2-sorption studies, diffuse reflectance measurement–UV-Vis spectrophotometers (DR-UV-vis), NH3-temperature-programmed desorption (NH3-TPD)/H2-Temperature programmed reduction (H2-TPR), Laser-Raman, high resolution transmission electron microscopy (HRTEM) and fourier-transform infrared spectroscopy (FT-IR) techniques. The activity of materials was investigated in hydrodeoxygenation (HDO) of jojoba oil to produce long-chain hydrocarbons at 225–375 °C under 10–40 bar H2 pressure in a stainless steel fixed bed reactor. Among the catalysts tested, Ni-MoS/Zr-K (10) exhibited the highest catalytic activity of 90% conversion and 79% yield of C18–C22 hydrocarbon. The structure-activity relationships and product distributions were also discussed in detail.

Sc2O3-promoted composite of In2O3 and Beta zeolite for direct conversion of bio-ethanol to propylene

A series of Sc2O3-modified (1–5%) In2O3/Beta composites were prepared by the deposition-precipitation method. These catalysts were characterized by X-ray diffraction, N2 adsorption, temperature-programmed desorption of NH3 and CO2, temperature-programmed reduction, X-ray photoelectron spectroscopy and 27Al magic-angle spinning nuclear magnetic resonance. The incorporation of Sc2O3 into In2O3/Beta results in enhanced catalyst stability for the conversion of ethanol to propylene, which is due to inhibition of the reduction of In3+ to In0 upon Sc2O3 modification.

Catalytic Oxidation of Trichloroethylene over RuO2 Supported on Ceria-zirconia Mixed Oxide

Ru/Ce-Zr catalysts were prepared by impregnation of Ru on the hydrothermally synthesized Ce-Zr mixed oxide with different molar ratio of Ce/Zr. The resultant products were systematically characterized by inductively coupled plasma(ICP), X-ray diffraction(XRD), scanning electron microscopy(SEM)/energy dispersive spectrometry(EDS), H2-temperature programmed reduction(H2-TPR), NH3-temperature programmed desorption(NH3-TPD) and X-ray photoelectron spectroscopy(XPS). It was proved by H2-TPR and NH3-TPD that the introduction of Ru can improve the activity of oxygen of catalysts and the presence of Zr contributes to the increments of acid properties of catalysts. When the molar ratio of Ce-Zr was 8:4, the quantity of Ru was 0.9%(mass ratio), and the calcined temperature of catalysts was at 400 °C, the removal rate of 90% for trichloroethylene(TCE) was reached at 250 °C for 5360 mg/m3 TCE and the stability of the catalysts was investigated under the condition. The results showed that the high removal rate can be maintained for at least 90 h, which is promising for industrial application.

Decomposition reaction of methylcyclohexane using H-ZSM-5 supported on NiCrAl metal foam

The endothermic reaction of the fuel is used as a cooling system for hypersonic aircraft. At this time, the zeolite catalyst is used for an effective endothermic reaction. In this work, the effect of metal foam catalyst on the composition of the product was investigated by using zeolite with a metal foam support as a catalyst for the endothermic reaction. The metal foam support was made with NiCrAl alloy. The characteristics of the zeolite catalyst were confirmed by X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR) analysis and NH3-Temperature programmed desorption (NH3-TPD) analysis. The composition of the product of the endothermic reaction was analyzed by GC–MS. In experiments of H-ZSM-5 catalyst pellet, the conversion of methylcyclohexane (MCH) was about 82%. While, in the case of the H-ZSM-5 catalyst supported with the metal foam, the conversion of MCH was about 93% and the conversion was 11% higher than that of the zeolite catalyst itself. In addition, experimental results with different temperatures showed that MCH conversion and aromatic hydrocarbon increased with increasing temperature. On the other hand, low hydrocarbons increased when increasing from 598 to 633 K, but decreased when increasing to 673 K.

3D-printed ZSM-5 monoliths with metal dopants for methanol conversion in the presence and absence of carbon dioxide

The development of effective strategies to utilize CO2 as a renewable feedstock for producing commercially-viable products is an interesting challenge to explore new concepts and opportunities in catalysis and industrial chemistry. In this study, 3D-printed ZSM-5 monoliths doped with Ga2O3, Cr2O3, CuO, ZnO, MoO3, and Y2O3were synthesized using the state-of-art 3D printing technique. The physicochemical properties of the catalysts were characterized by X-ray diffraction, N2 physisorption, NH3 and CO2 temperature-programed desorption and H2 temperature-programmed reduction. The promotional effect of doped metals on catalytic performance of 3D-printed ZSM-5 monoliths in methanol to hydrocarbon (MTH) reaction in the presence and absence of CO2 was investigated. Results indicated that both metal dopants type and reaction atmosphere greatly influence catalyst stability and product distribution. The yield of light olefins was enhanced over all metal-doped 3D-printed ZSM-5 monoliths in N2 atmosphere (absence of CO2), however, CO2 atmosphere did not favor the production of light olefins. Although selectivity toward ethylene slightly decreased, the propylene yield was almost constant after switching N2 to CO2 in MTH reaction at 400 °C. Furthermore, it was found that Y- and Zn-doped ZSM-5 monoliths exhibited higher yield of light olefins and BTX compounds in the in the absence and presence of CO2, respectively.