稠油地下改质开采技术及发展趋势

稠油作为全球重要的非常规原油资源，是保障我国能源安全、重大工程需求的重要资源。目前常规的热采稠油油藏陆续进入开采后期，高能耗、高污染、高成本问题日趋严重，亟需依靠技术换代实现开发方式升级。稠油地下改质是通过向油藏中注入改质催化剂，使其与稠油发生化学反应，实现稠油地下不可逆降黏并高效采出的一种开采方式，是近十年来最受瞩目的下一代稠油开采技术之一。本文从技术机理、改质催化剂及开采效果影响因素三方面阐述了技术内涵，通过系统调研国内外相关学者和企业的代表性成果，按照催化剂种类、反应温度和降黏效果等进行综合性分类统计，对比了现有矿场试验的开采方式和采油效果，指出制约技术应用的两个关键问题，并展望了技术未来发展方向。     

Facile synthesis of polyoxometalate-based composite with doped ternary NiCoFe cations as electrocatalyst for oxygen evolution reaction

The construction of efficient and low-cost electrocatalysts for oxygen evolution reactions (OER) to replace precious catalysts is a necessity to achieve economic production of hydrogen. Herein, we report an efficient tri-metallic electrocatalysts for the OER that is prepared by incorporate nickel, cobalt and iron cations on Triton X-100/phosphotungstic acid organic-inorganic composite without utilize any binders or energy consumer procedure. Considering to the synergy effect of simultaneous absorption of NiCoFe cations on composite substrate, the as-made tri-metallic catalyst exhibits excellent OER activity with a small overpotential of 210 and 330 mV at a current density of 10 and 100 mA cm^?2, respectively. Moreover, remarkable trends in electrocatalytic activity of mono-, bi- and tri-metallic electrocatalysts at low (10 mA) and high (100 mA) current density are observed. In addition, this new families of non-precious metal catalyst shows long-term durability in 1 M KOH.     

Solution plasma-assisted preparation of highly dispersed NiMnAl-LDO catalyst to enhance low-temperature activity of CO2 methanation

In this work, the solution plasma-assisted method was used to prepare NiMnAl-LDO (layered double oxides) catalysts with different treatment times, which were used for the CO₂ methanation reaction. Solution plasma treatment can enhance the dispersibility of the catalyst, create oxygen defects and improve the chemical adsorption capacity of the catalyst. The results show that the low-temperature activity of the catalyst has been improved after the solution plasma treatment. We demonstrate that the NiMnAl-LDO-P(20) catalyst with high dispersion has the highest catalytic activity in CO₂ methanation (81.3% CO₂ conversion and 96.7% CH₄ selectivity at 200 °C). Even though working for 70 h, the catalyst is still highly stable. This work provides a great promise for improving the low-temperature activity of Ni-based catalysts.     

Amorphous-crystalline cobalt-molybdenum bimetallic phosphide heterostructured nanosheets as Janus electrocatalyst for efficient water splitting

Efficient and sustainable Janus catalysts toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are highly desirable for future hydrogen production via water electrolysis. Herein we report an active Janus electrocatalyst of amorphous-crystalline cobalt-molybdenum bimetallic phosphide heterostructured nanosheets on nickel foam (CoMoP/CoP/NF) for efficient electrolysis of alkaline water. As-reported CoMoP/CoP/NF consists of amorphous bimetal phosphide nanosheets doped with crystalline CoMoP/CoP heterostructured nanoparticles on NF. It can efficiently catalyze both HER (η = 127 mV@100 mA cm^?2) and OER (η = 308 mV@100 mA cm^?2) in alkaline electrolyte with long-term durability. Serving as anode and cathode of water electrolyzer, CoMoP/CoP/NF generates electrolytic current of 10, 50 and 100 mA cm^?2 at low voltage of 1.50, 1.59, and 1.67 V, respectively.     

Effect of Ni ratio on mesoporous Ni/MgO nanocatalyst synthesized by one-step hydrothermal method for thermal catalytic decomposition of CH4 to H2

The Ni/MgO catalysts were synthesized by hydrothermal method and the effect of changes in nickel ratio on the physicochemical properties and catalytic performance were investigated for TCD of CH₄ to H₂. In all catalysts, the only NiO–MgO phase as solid solution was formed, and crystals size were in the nanoparticles range. The results confirmed that the catalysts with mesoporous structure and high porosity were successfully synthesized by one step in the absence of surfactants. The increasing nickel ratio from 10 to 40 wt% increases the methane conversion from 28.3 to 48.6% and hydrogen yield from 33.2 to 53.2%, respectively. Also, the stability of catalysts depends on the amount and size of nickel particles in the structure of the catalysts. Among the catalysts, 40 and 30 wt% showed the highest initial activity (48.6% methane conversion) and the highest stability (above 45% hydrogen yield for 180 min), respectively.     

Nitrogen-phosphorus co-functionalized reduced graphene oxide supported NiCoPd-CeOx nanoparticles as a highly efficient and stable catalyst for formic acid dehydrogenation

Formic acid (HCOOH, FA), a common liquid hydrogen storage material, has attracted tremendous research interest. However, the development of efficient, low-cost and high-stable heterogeneous catalyst for selective dehydrogenation of FA remains a major challenge. In this paper, a simple co-reduction method is proposed to synthesize nitrogen-phosphorus co-functionalized rGO (NPG) supported ultrafine NiCoPd-CeO_x nanoparticles (NPs) with a mean size of 1.2 nm. Remarkably, the as-prepared Ni_0.2Co_0.2Pd_0.6-CeO_x/NPG shows outstanding catalytic activity for FA dehydrogenation, affording a high TOF value of 6506.8 mol H₂ mol Pd^?1 h^?1 at 303 K and a low activation energy of 17.7 kJ mol^?1, which is better than most of the reported heterogeneous catalysts, and can be ascribed to the combined effect of well-dispersed ultrafine NiCoPd-CeO_x NPs, modified Pd electronic structure, and abundant active sites. The reaction mechanism of dehydrogenation of FA is also discussed. Furthermore, the optimized Ni_0.2Co_0.2Pd_0.6-CeO_x/NPG shows excellent stability over 10^th run with 100% conversion and 100% H₂ selectivity, which may provide more possibilities for practical application of FA system on fuel cells.     

Research progress on catalysts for hydrogen generation through sodium borohydride alcoholysis

Hydrogen is a promising energy carrier for realizing the transition from fossil fuels to renewable energy sources. Nowadays, the development of the hydrogen economy faces many challenges connected with its efficient production, storage, distribution, and end-use. During the past decade, the alcoholysis, particularly methanolysis, of sodium borohydride (NaBH₄) has attracted much attention due to the nonflammability, nontoxicity, potential for utilization in cold conditions of the reaction system. Highly efficient catalysts are of great significance to guarantee the efficiency of the reaction and control the hydrogen release. In this review, we summarize recent advances in both metallic and nonmetallic catalysts for the alcoholysis of NaBH₄. This review also summarizes the advantages and disadvantages of various catalysts in the investigations to assess the potential opportunities and challenges for their application in NaBH₄ methanolysis. The catalytic mechanisms related to NaBH₄ methanolysis were also discussed.     

Electrodeposition of the manganese-doped nickel-phosphorus catalyst with enhanced hydrogen evolution reaction activity and durability

Hydrogen technology is widely considered a novel clean energy source, and electrolysis is an effective method for hydrogen evolution. Therefore, efficient hydrogen evolution reaction (HER) catalysts are urgently needed to replace precious metal catalysts and meet ecological and environmental protection standards. Herein, Ni–Mn–P electrocatalysts are synthesized using facile electrodeposition technology. The influence of the Mn addition on the catalytic behavior is studied by the comprehensive analysis of catalytic performance and morphology of the catalysts. Among them, the Ni–Mn–P0.01 catalyst exhibits small coral-like structures, greatly improving the adsorption and desorption of hydrogen ions and reducing the overpotential hydrogen evolution. Consequently, overpotential at 10 mA cm^?2 electric current density is 113 mV, and the value of the Tafel slope achieves 74 mV/dec. Furthermore, the Ni–Mn–P catalyst shows long-time (20 h) stability at current densities of 10 and 60 mA/cm². The results confirm that the synergistic effect of Ni, Mn, and P accelerates the electrochemical reaction. Meanwhile, the addition of manganese element can change the micromorphology of the catalyst, thereby exposing more active sites to participate in the reaction, enhancing water ionization, improving the catalytic performance. This study opens a new way toward improving the activity of the catalyst by adjusting Mn concentration during the electrodeposition process.     

Recent trends in the development of reactor systems for hydrogen production via methanol steam reforming

Hydrogen is currently receiving significant attention as an alternative energy resource, and among the various methods for producing hydrogen, methanol steam reforming (MSR) has attracted great attention because of its economy and practicality. Because the MSR reaction is inherently activated over catalytic materials, studies have focused on the development of noble metal-based catalysts and the improvement of existing catalysts with respect to performance and stability. However, less attention has been paid to the modification and development of innovative MSR reactors to improve their performance and efficiency. Therefore, in this review paper, we summarize the trends in the development of MSR reactor systems, including microreactors and membrane reactors, as well as the various structured catalyst materials appropriate for application in complex reactors. In addition, other engineering approaches to achieve highly efficient MSR reactors for the production of hydrogen are discussed.     

Metal-free catalyst fabrication by incorporating oxygen groups on the surface of the carbonaceous sample and efficient hydrogen production from NaBH4 methanolysis

In the present study, metal-free catalysts for efficient H₂ generation from NaBH₄ methanolysis was produced for the first time from apricot kernel shells with two-step activation. The first stage of the two-stage activation includes the production of activated carbon with the KOH agent (AKOH), and the second stage includes hydrothermally HNO₃ activation with oxygen doping (O doped AKOH + N). The hydrogen production rate (HGR) and the activation energy (Ea) of the reaction with the obtained metal-free catalyst (10 mg) were determined as 14,444 ml min^?1 g^?1 and 7.86 kJ mol^?1, respectively. The structural and physical-chemical properties of these catalysts were characterized by XRD (X-ray diffraction), SEM (scanning electron microscopy), elemental CHNS analysis, FT-IR (Fourier transform infrared spectroscopy), and nitrogen adsorption analysis. Also, the reusability results of this metal-free catalyst for H₂ production are promising.