Catalysts For Steam Reforming Of Methanol Research Articles

Hydrolysis Precipitation Method for the Preparation of Cu‐ZnO@Al2O3 Catalyst in Methanol Steam Reforming

AbstractA hydrolysis precipitation method was developed to prepare Cu based catalyst for methanol steam reforming. A comparison of the hydrolysis precipitation and the conventional coprecipitation method was conducted. The test results present that Cu‐ZnO@Al2O3 prepared by hydrolysis precipitation exhibits better catalytic activity and stability in MSR reaction. XRD, XRF, EDS, SEM, TPR, XPS and N2 adsorption/desorption reveal that the high catalytic performance of Cu based catalyst from hydrolysis precipitation could be attributed to developed pore organization, surface enrichment of active components and higher reducibility.

Insights into direct/synergetic processes for high-efficiency steam reforming of methanol over Pt-In2O3/CeO2 catalysts: The effect of support structural properties

The addition of Pt (1 %) and In2O3 (7 %) phases into CeO2 supports exhibited an interaction, resulting in the formation of bifunctional Pt2+-In2O3-CeO2, Ptδ+-CeO2 (0 < δ < 2), In2O3-CeO2, and inactive In2O3 macroparticles., Low CO selectivity was achieved in methanol steam reforming (MSR) by sacrificing methanol conversion/catalytic stability. Two distinct reaction paths were identified, viz., the direct process over bifunctional Pt2+-In2O3-CeO2 and the synergetic process between Ptδ+-CeO2 and In2O3-CeO2. The relative ratio of these two processes played a decisive role in determining the product distribution. The direct process improved methanol conversion while maintaining low CO selectivity. However, a decrease in catalytic stability was attributed to the agglomeration and sintering of the In2O3 phase, leading to the conversion of Pt2+-In2O3-CeO2 into Ptδ+-CeO2. To address the challenge of balancing methanol conversion/catalytic stability and CO selectivity, it was crucial to enhance Pt2+-In2O3-CeO2 sites and preserve their stability. Furthermore, the structural properties of the support played a significant role in governing the distributions and states of Pt and In2O3 phases. Specifically, the use of CeO2 (0.5 °C min−1) support resulted in a substantial increase in Pt2+-In2O3-CeO2 and effectively mitigated the sintering of In2O3 phases, ensuring the stability of Pt2+-In2O3-CeO2. In conclusion, our work elucidated the intricate relationships among the structural properties of CeO2 supports, the distributions and states of Pt and In2O3 phases, and MSR performance over Pt-In2O3/CeO2 catalysts, which hold promise for advancing the development of high-performance MSR catalysts.

An Exsolved Cu Nanocatalyst for Highly Efficient Methanol Steam Reforming

AbstractBaZr0.1Ce0.7Y0.2O3 (BZCY) perovskite with in‐situ exsolved metallic Cu catalyst acted as a catalyst for methanol steam reforming (MSR) for the first time. After reduction at 550 °C for 3 hours, fine and uniform metallic Cu nanoparticles were exsolved from the perovskite lattice with more active sites and oxygen vacancies on the surface. The reduced Ba0.9Zr0.1Ce0.7Y0.1Cu0.1O3 (BZCYCu) displayed a stable conversion of methanol above 99.9 % at 500 °C within 120 hours, with a negligible amount of CO in the outlet gas and no carbon species was detected on the surface of catalyst. The BZCYCu gained 7.4 % of their weight at 500 °C during the water vapor adsorption stage in temperature programmed water absorption experiment, which showed a considerable water adsorption capacity. Such a hygroscopicity could promote the catalytic methanol steam reforming and CO elimination. And metallic Cu has also been widely applied for the methanol steam reforming reaction due to their high activity and carbon resistance. The synergy of metallic Cu nanoparticles and perovskite substrate with more oxygen vacancies and well hydroscopicity improved the structural stability and ensured the catalytic activity of RBZCYCu catalysts.

Cu/REO (RE = La, Pr, Sm, Y, Ce) catalysts for methanol steam reforming: Understanding the interaction between Cu and individual REO supports

With the objective to develop applicable catalysts for methanol steam reforming (MSR) to generate H2, five individual REOs were prepared as supports for Cu/CuO to understand the Cu/CuO-support interaction. Pure REO supports with a cubic phase are successfully fabricated except that monoclinic La2O2CO3 carbonate is formed for La2O3 sample, which has negative effect on the reaction. The reaction performance ranks as 5 % Cu/CeO2 > 5 % Cu/Sm2O3 > 5 % Cu/Pr6O11 > 5 % Cu/Y2O3 > 5 % Cu/La2O3 for the samples. It has been disclosed that the quantities of surface basic sites, active O2– species, Cu+ contents/percentage and active Cu surface area are positively correlated to the reaction performance. Thus, the interaction together of these four factors decides the reaction performance. In addition, In-situ DRIFTS results of CH3OH adsorbing/steam reforming have demonstrated that on the optimal 5 % Cu/CeO2, the reactive monodentate m-HCOO* intermediate is formed, which is absent on 5 % Cu/Y2O3 with worse performance.

Enhanced metal−promoter interaction over Na modified Co2C nanoprisms for high-efficiency hydrogen production from methanol steam reforming

As an important application for methanol-based energy-storage systems, methanol steam reforming (MSR) using appropriate catalysts can provide clean hydrogen via onboard production for fuel cells. However, owing to their unsatisfactory activity and stability, the use of the most common catalysts, including Cu-based and groups 8–––10 transition metals, remains challenging. Herein, a series of Na-promoted Co2C nanoprism catalysts containing different Na loadings was used for the first time in MSR. The 1Na/Co2C catalyst showed an excellent activity and stability for MSR, with H2 production rates as high as 4637.9 μmol/gcat/min at 250 °C, which outperforms most of the reported catalysts. In-depth characterizations revealed that a strong interaction between Na and Co2C stabilized the catalyst and promoted the dissociation of CH3OH and H2O. A further investigation of the reaction mechanism revealed that the reaction proceeded via the dehydrogenation of methanol and sequential water−gas shift reactions. Density functional theory calculations revealed that the Co2C (101) surface exhibited the lowest energy barrier and that the methoxy dehydrogenation was the rate-determining step. This work provides further valuable insights into the rational design of transition-metal carbide catalysts for MSR.

Fe–Ni–Ce–Zr-modified CuO–ZnO catalyst for methanol steam reforming

Four copper-based catalysts were prepared by co-precipitation method. The catalysts were characterized by scanning electron microscopy, N2 adsorption-desorption, temperature programmed reduction process (H2-TPR), X-ray diffraction (XRD) and in-situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) to explore the effects of different components on catalyst activity. The performance of different catalysts for hydrogen production via methanol steam reforming was evaluated on a fixed-bed reactor. The effects of different components, reaction temperature and gas hourly space velocity (GHSV) on the catalytic performance were investigated. The results exhibited that among the investigated catalysts, 1# and 2# catalysts had the higher catalytic activity and stability. Under the conditions of 280 °C, a molar ratio of methanol to water of 1:1.3, and a GHSV of 13.3 L/(g·h), the methanol conversion rate reached 99.9%, the CO concentration was as low as 0.29%, and the selectivity was only 1.16%. The H2 production flow rate per unit mass of catalyst was 270 mL/(min·g). After 60 h of start-stop experiments, the methanol conversion rate remained above 98.4%, the CO concentration was always lower than 0.5%, and the start-up speed was significantly faster than that of the commercial catalyst M650. This study provided an effective method for the preparation of catalysts for methanol steam reforming.

Interface-hydroxyl enabling methanol steam reforming toward CO-free hydrogen production over inverse ZrO2/Cu catalyst

Methanol steam reforming (MSR), as an ideal on-site hydrogen production process, is urgently calling for a groundbreaking catalyst with ultralow or even no CO formation. Herein, we report a promising inverse ZrO2/Cu catalyst system obtained by oxalate sol-gel co-precipitation and subsequent calcination/H2-reduction treatment, boosting the MSR process toward CO-free hydrogen production. The preferred ZrO2-0.1/Cu (Zr/Cu molar ratio of 0.1) achieves a high H2 productivity of 190 mmolH2 gcat−1 h−1 with undetectable CO production at 200 °C for a feed of CH3OH/H2O (1/1, mol/mol), while showing no deactivation throughout 200-h test by taking advantage of high sintering resistance of the inverse structure. As experimentally and theoretically unveiled, the specific ZrO(OH)-(Cu+/Cu) interfacial structure is formed during the reaction, offering highly reactive interfacial -OH to convert HCHO* (formed on Cu+/Cu sites from methanol; decomposable to CO/H2) into H2 and CO2 via HCOOH* intermediate. These findings will be instrumental to tailor more-advanced MSR catalysts.

Probing crystalline phase effect of rare earth metal oxides (REO) on Cu/REO (RE=Gd, Eu, Sm) catalysts for methanol steam reforming (MSR) to produce H2

In this work, to study the phase structure effect, three groups of Cu/REO catalysts were prepared with cubic and monoclinic Gd2O3, Eu2O3 and Sm2O3 supports for MSR reaction to produce H2. Based on CH3OH conversion and H2 yield, the reaction performance of the catalysts ranks as Cu/Sm2O3-M > Cu/Sm2O3–C > Cu/Gd2O3-M > Cu/Gd2O3–C > Cu/Eu2O3-M > Cu/Eu2O3–C. For the same kind of REO, Cu supported on the monoclinic support shows better performance than on the cubic one. Despite the phase structure difference, Sm2O3 is the best support among all the three kinds of REOs. Compared with Cu/REO catalysts prepared with cubic supports, the corresponding catalysts prepared with monoclinic supports generally possess more surface oxygen vacancies, which can generate more surface active oxygen (O2–) and moderate basic sites. Moreover, the contents of Cu + on the catalysts follow the same sequence. The reaction performance is positively related to the amount of these three types of surface sites. But metallic Cu0 species is necessary to maintain the Cu+ ↔ Cu0 redox cycle. Furthermore, on a catalyst with good performance, those vital surface reaction intermediates can be stabilized during the reaction. Cu/Sm2O3-M possesses the largest quantities of these surface sites, and has the appropriate amount of Cu+ and Cu0 after reduction, thereby displaying the optimal performance in all the catalysts. In conclusion, evident support crystal structure effect is observed for Cu/REO catalysts, and a monoclinic phase REO is a better support than the respective cubic phase one.

Techno-economic assessment of hydrogen production via dimethylether steam reforming and methanol steam reforming

ABSTRACT The present work reports the techno-economic analysis of hydrogen generation using Dimethyl Ether Steam Reforming (DMESR) and Methanol Steam Reforming (MSR) processes. For both processes, steady-state simulation models were developed using Aspen Plus. The two processes are analysed by taking into account the kinetics of the Cu/ZnO/Al2O3 catalyst for MSR and Cu–Ni/γ-Al2O3 catalyst for DMESR in an RPLUG model simulated as a Fixed Bed Reactor (FBR) at a temperature of 250°C and pressure 20 bar. The work dives into heat integration opportunities to reduce the operating cost of the two processes. The article also provides a gist of the approximate cost to produce hydrogen by the two processes by taking into consideration the cost of equipment and utilities involved. It is found that the TAC for DMESR is marginally higher than MSR mainly because of the higher cost of utilities involved. It was also found that NPV for MSR is comparatively higher than DMESR. The article also provides TAC for Selective Methanation of Carbon Monoxide (SMC) for both processes with the purpose of minimising CO.

Influence of ceria existence form on deactivation behavior of Cu-Ce/SBA-15 catalysts for methanol steam reforming

Methanol steam reforming (MSR) is promising in hydrogen production. Cu-SBA-15 and Cu–Ce/SBA-15-I suffer poor selectivity owing to sluggish steam activation on Cu0-SBA-15. And small Cu0 tend to sinter due to Ostwald ripening. Sintering can be avoided by modifying SBA-15 with Ce ion exchange, where Si–OH groups are replaced by Si–O–Ce. Ceria existence form varies from patches to small particles as exchange times increase. In Cu–Ce/SBA-15, ceria patches strongly interact with Cu, which promotes steam activation, hence the catalyst exhibit remarkable activity and selectivity. In Cu–3Ce/SBA-15, ceria patches grow into small ceria particles (<5 nm) after repeated ion exchange. Ceria particles tend to be over-reduced, thus accounting for carbonaceous deposits on excessive Ce3+. Such deactivation is reversible, and catalytic performance can resume after air exposure. This study reveals that deactivation behavior of MSR catalysts can be modified by existence and size effect of ceria, which is worth referring to in further MSR catalyst synthesis.

A Mechanistic Study of Methanol Steam Reforming on Ni2P Catalyst

Methanol steam reforming (MSR) is a promising technology for on-board hydrogen production in fuel cell applications. Although traditional Cu-based catalysts demonstrate high catalytic activity and selectivity towards CO2 relative to CO, which is produced via methanol decomposition, they suffer from poor thermal stability and rapid coke formation. Nickel phosphides have been widely investigated in recent years for many different catalytic reactions owing to their remarkable activity and selectivity, as well as their low cost. In this work, we present a mechanistic study of methanol decomposition and MSR pathways on Ni2P using density functional theory (DFT) calculations. DFT-predicted enthalpic barriers indicate that MSR may compete with methanol decomposition on Ni2P, in contrast to other transition metals (e.g., Pt, Pd, and Co) which primarily decompose methanol into CO. The formaldehyde intermediate (CH2O*) can react with co-adsorbed hydroxyl (OH*) from water dissociation to produce H2COOH* which then undergoes subsequent dehydrogenation steps to produce CO2 via H2COOH*→ HCOOH* → HCOO* → CO2. We also examined the conversion of CO into CO2 via the water–gas shift (WGS) reaction, but we ruled out this pathway because it exhibits high activation barriers on Ni2P. These findings suggest that Ni2P is a promising new catalyst for MSR.

Steam reforming of methanol for hydrogen production over attapulgite-based zeolite-supported Cu-Zr catalyst

The methanol steam reforming (MSR) was one of the promising technologies for high-efficiency hydrogen production. The key issue for MSR was the development of catalysts. In this paper, the Cu-Zr components supported on the attapulgite-based zeolite (AZ) was prepared and applied into MSR reaction. MSR activity test demonstrated the synthesized micropore and mesopore channels in AZ enhanced the catalytic performance through promoting the heat and mass transfer. Various characterizations such as N2 adsorption–desorption, XRD, H2-TPR, XPS, SEM, HRTEM, H2/CO2-TPD, H2 pulse chemisorption and TGA confirmed Zr addition significantly increased the distribution of active metal particles and metallic surface area and facilitated the formation of Cu0/Cu+-ZrOxHy interface sites. Among the prepared catalysts, 1Cu1Zr/AZ catalyst possessed the maximum Cu0/Cu+-ZrOxHy interface sites and metallic surface area, therefore it exhibited the best catalytic performance for MSR, and its hydrogen productivity reached to 655.1 mmol/gcat/h. In addition, the Cu0/Cu+-ZrOxHy interface sites in Zr-modified Cu/AZ catalysts inhibited the active metal sintering and coke formation. The possible mechanism of MSR over 1Cu1Zr/AZ was proposed, in which Cu0/Cu+ species promoted the decomposition of methanol and intermediates, meanwhile, the Cu0/Cu+-ZrOxHy interface sites helped to continuously provide the –OH groups through steam activation by hydroxylated Zr species. These cooperative effects promoted the oxidation of intermediates and water–gas shift reaction, resulting in producing more H2 and CO2. This work offers a possibility for preparing available and economical attapulgite-based zeolite-supported Cu-Zr Catalyst for MSR.

Hydrogen generation by methanol steam reforming process by delafossite-type CuYO2 nanopowder catalyst

Due to global warming, the energy crisis, and climate change, hydrogen is to be used as an alternate renewable energy source. In industry, hydrogen generation is mainly obtained by the natural gas steam reforming reaction. In this study, delafossite CuYO 2 nanopowder was used as a catalyst for methanol steam reforming (MSR). The delafossite-structured CuYO 2 nanopowder was synthesized by the glycine nitrate process, annealed in N 2 , and used for MSR. The influences of different annealing temperatures on the phase transformation, surface area, and crystal structure composition of the Cu–Y–O powder were examined. The characteristics of the CuYO 2 nanopowder were identified by X-ray diffraction studies, Brunauer-Emmett-Teller studies (BET), field emission scanning electron microscopy studies, transmission electron microscopy, and X-ray photoelectron spectroscopy. The BET studies indicated that the surface area of the CuYO 2 nanopowder varied from 2 to 16 m 2 /g before and after annealing at different temperatures because of structural transformation. Scanning electron microscopy of the CuYO 2 nanopowder revealed a porous structure formed by the large amount of gas released during the glycine-nitrate process. Moreover, when the self-combusted nanopowder was annealed in N 2 at 750 °C, the porous structure of the CuYO 2 nanopowder was retained. The CuYO 2 catalyst in MSR performance was estimated, and the hydrogen generation rate reached as high as 1735.65 ml STP min −1 g-cat −1 at 300 °C without reduction treatment. Besides, the CuYO 2 catalyst exhibit a higher hydrogen production rate at a lower temperature. The hydrogen generation performance of this CuYO 2 catalyst could be of great importance in industry and have a global economic impact. Hydrogen generation over the delafossite-Type CuYO 2 nanopowder catalyst. • CuYO 2 catalyst was prepared by a self-combusted glycine nitrate process. • CuYO 2 catalyst was applied for the methanol steam reforming. • The surface area of CuYO 2 powder varied from 2.9 to 16 m 2 /g. • The CuYO 2 exhibited hydrogen production rate as 1735.65 ml/min g-cat at 300 °C. • The CuYO 2 exhibit the higher hydrogen production rate at lower temperature.

The sol-gel autocombustion as a route towards highly CO2-selective, active and long-term stable Cu/ZrO2 methanol steam reforming catalysts.

The adaption of the sol–gel autocombustion method to the Cu/ZrO2 system opens new pathways for the specific optimisation of the activity, long-term stability and CO2 selectivity of methanol steam reforming (MSR) catalysts. Calcination of the same post-combustion precursor at 400 °C, 600 °C or 800 °C allows accessing Cu/ZrO2 interfaces of metallic Cu with either amorphous, tetragonal or monoclinic ZrO2, influencing the CO2 selectivity and the MSR activity distinctly different. While the CO2 selectivity is less affected, the impact of the post-combustion calcination temperature on the Cu and ZrO2 catalyst morphology is more pronounced. A porous and largely amorphous ZrO2 structure in the sample, characteristic for sol–gel autocombustion processes, is obtained at 400 °C. This directly translates into superior activity and long-term stability in MSR compared to Cu/tetragonal ZrO2 and Cu/monoclinic ZrO2 obtained by calcination at 600 °C and 800 °C. The morphology of the latter Cu/ZrO2 catalysts consists of much larger, agglomerated and non-porous crystalline particles. Based on aberration-corrected electron microscopy, we attribute the beneficial catalytic properties of the Cu/amorphous ZrO2 material partially to the enhanced sintering resistance of copper particles provided by the porous support morphology.

Methanol Steam Reforming over ZnPt/MoC Catalysts: Effects of Hydrogen Treatment

Molybdenum carbide-based catalysts have been utilized widely in hydrogen production from methanol steam reforming (MSR) because of their high selectivity to H₂ and low reaction temperature. However, the catalytic performance and stability for MSR are highly vulnerable to the method and condition of catalyst preparation. Here, ZnPt/MoC catalysts synthesized by different processing techniques were used for the production of hydrogen from MSR at low temperature with emphasis on the influence of hydrogen treatment on the catalytic performance and stability. These ZnPt/MoC catalysts were analyzed fully using several characterization techniques. From the results, it was found that reducing the ZnPt/MoC catalyst precursor before the carburization facilitated the formation of the α-MoC₁ – ₓ phase and enhanced the platinum dispersion on the catalyst surface, which resulted in increased catalytic performance and stability for MSR. Furthermore, after treating with flowing hydrogen at 200–400 °C, more α-MoC₁ – ₓ phase and highly dispersed platinum particles were obtained in the modified catalysts. The optimal ZnPt/MoC-p3–200 catalyst exhibited outstanding catalytic performance for MSR and extremely low CO selectivity at low reaction temperature. This study provides a perspective on the design and synthesis of stable and highly active molybdenum carbide-based catalysts for MSR.

Production of hydrogen from methanol steam reforming using CuPd/ZrO2 catalysts – Influence of the catalytic surface on methanol conversion and CO selectivity

Electricity generation for mobile applications by proton exchange membrane fuel cells (PEMFCs) is typically hindered by the low volumetric energy density of hydrogen. Nevertheless, nearly pure hydrogen can be generated in-situ from methanol steam reforming (MSR), with Cu-based catalysts being the most common MSR catalysts. Cu-based catalysts display high catalytic performance, even at low temperatures (ca. 250 °C), but are easily deactivated. On the other hand, Pd-based catalysts are very stable but show poor MSR selectivity, producing high concentrations of CO as by-product. This work studies bimetallic catalysts where Cu was added as a promoter to increase MSR selectivity of Pd. Specifically, the surface composition was tuned by different sequences of Cu and Pd impregnation on a monoclinic ZrO2 support. Both methanol conversion and MSR selectivity were higher for the catalyst with a CuPd-rich surface compared to the catalyst with a Pd-rich surface. Characterization analysis indicate that the higher MSR selectivity results from a strong interaction between the two metals when Pd is impregnated first (likely an alloy). This sequence also resulted in better metallic dispersion on the support, leading to higher methanol conversion. A H2 production rate of 86.3 mmol h−1 g−1 was achieved at low temperature (220 °C) for the best performing catalyst.

Methanol steam reforming for hydrogen production over ternary composite ZnyCe1Zr9Ox catalysts

Developing the catalysts for methanol steam reforming (MSR) via interfacial construction still remains many challenges. In this study, the effects of ZnO content on the performance of ZnyCe1Zr9Ox were studied for MSR. The best-performing Zn1Ce1Zr9Ox catalyst exhibited full methanol conversion and higher H2 production rate of 0.31 mol·h−1·gcat−1 at 400 °C. Characterization results revealed the synergistic effect among ZnO, CeO2 and ZrO2 after forming a solid solution and the incorporation of Zn2+ into Ce1Zr9Ox matrix not only modulate the ratio of surface OLatt/OAds, but also generate new Zn–O–Zr interfacial structure corresponding to the lattice/bridge oxygen to increase the selectivity of CO2. The excess oxygen vacancies on the samples surface favor the decomposition of methanol to generate the undesired CO. This study proposes a new design strategy for developing highly efficient composite MSR catalysts by control of the lattice/bridge oxygen and surface oxygen vacancy.

Low-temperature hydrogen production from methanol steam reforming on Zn-modified Pt/MoC catalysts

Methanol steam reforming (MSR) is a promising process to produce hydrogen suitable for polymer electrolyte membrane fuel cells, but the development of catalysts with high activity and selectivity at low temperature is highly needed. Here, a series of Zn-modified Pt/MoC catalysts with different Zn loadings were prepared and used to produce hydrogen by MSR at low temperature. The addition of small amounts of Zn to Pt/MoC not only favors the formation of α-MoC1-x phase, but also enhances the Pt dispersion and the interaction between α-MoC1-x and Pt active sites, leading to increased catalytic activity for MSR. The optimal 0.5Zn-Pt/MoC catalyst exhibits superior hydrogen production activity with exceptionally low CO selectivity at low temperatures (120–200 °C). Overall, this work offers insight into the structure-activity relationship and stability in Zn-modified Pt/MoC catalysts for MSR, which will be helpful to the design of MSR catalysts with high activity and stability at low temperature.

Copper zinc oxide nanocatalysts grown on cordierite substrate for hydrogen production using methanol steam reforming

Hydrogen production from methanol rather than the traditional source, methane, is considered to be advantageous in ease of transportation and storage. However, the current copper-based catalysts utilized in methanol steam reforming are associated with challenges of sintering at high temperature and production of CO which could poison fuel cells. In addressing these challenges, ZnO nanorods were grown hydrothermally on the surface of cordierite and impregnated with Cu to produce catalysts for methanol steam reforming. The catalysts were characterized using SEM, XRD, FTIR, XPS, BET and Raman Spectroscopy. A fixed-bed reactor was used for testing the catalysts while the reaction products were characterized using a GC fitted with FID and TCD. The effects of temperature, methanol concentration and particle size of catalysts on methanol steam reforming were investigated. The experiments were carried out between 180 and 350 °C. CO selectivity of 0% was observed for temperatures between 180 and 230 °C for 0.8 MeOH:1H2O with an average H2 selectivity of 98% for that temperature range. XPS showed that the catalyst was relatively unchanged after reaction while Raman spectroscopy revealed coke formation on the catalyst surface for reactions carried out above 300 °C. This shows that the catalyst is active and selective for the reaction.

Photo-assisted methanol steam reforming on solid solution of Cu-Zn-Ti oxide

Methanol steam reforming (MSR) is an attractive source of nearly-CO-free H2 for fuel cells. However the pre-reduction procedure in hydrogen for most of the developed oxide catalysts is costly both in time and energy. In this work, a photo-thermal hybrid system was used to achieve in situ activation of Cu-Zn-Ti oxide solid solution catalyst at low temperatures (200–210 °C) and a photo-promoted MSR process. Thanks to the synergetic effect of thermal and photon energies, the in situ activated Cu-Zn-Ti oxide exhibited optimal hydrogen evolution rates of 50.6 and 76.2 mmol/g/h and appreciable methanol conversions of 20% and 50% with zero selectivity to CO at 200 and 210 °C, respectively, which surpassed most of the reported Cu-based MSR systems. Furthermore, through a series of control experiments and in situ DRIFT study, the mechanism for the photo-assisted in situ activation and activity promotion was revealed. The findings in this work not only provide a new methodology for low-temperature in situ activation of Cu-based MSR catalysts but also could inspire the development of hybrid technologies for traditional systems.