The catalytic hydrogenation of CO2 to olefins has received considerable attention. Herein, transition metal- and sodium-modulated iron-based catalysts were fabricated. Doping with zinc and copper favor the formation of Fe3O4 and Fe5C2 active phases, while adding manganese inhibits the formation of iron carbide. In addition, phase separation between copper and iron species occurs more readily under working conditions. Therefore, a zinc- and sodium-modulated Fe catalyst exhibited the best activity and stability. Moreover, copper was predicted to substantially decrease the energy barrier of the rate-determining step for the secondary hydrogenation of olefins and result in a much lower olefin-to-paraffin ratio. In addition, the ZnO/Fe5C2 interface facilitated the desorption of olefins from the catalyst surface and inhibited the undesirable secondary reaction of olefins, enabling a high selectivity toward olefins of 36.9 % C2–4= and 32.3 % C5+=. This study provides an exemplary new strategy for tuning the product selectivity of catalysts for olefin synthesis. 

Selective synthesis of olefins via CO2 hydrogenation over transition-metal-doped iron-based catalysts

Converting carbon dioxide (CO2) into value-added fuels or chemicals through photothermal catalytic CO2 hydrogenation is a promising approach to alleviate the energy shortage and global warming. Understanding the nanostructured material strategies in the photothermal catalytic CO2 hydrogenation process is vital for designing photothermal devices and catalysts and maximizing the photothermal CO2 hydrogenation performance. In this Perspective, we first describe several essential nanomaterial design concepts to enhance sunlight absorption and utilization in photothermal CO2 hydrogenation. Subsequently, we review the latest progress in photothermal CO2 hydrogenation into C1 (e.g., CO, CH4, and CH3OH) and multicarbon hydrocarbon (C2+) products. Finally, the relevant challenges and opportunities in this exciting research realm are discussed. This perspective provides a comprehensive understanding for the light-heat synergy over nanomaterials and instruction for rational photothermal catalyst design for CO2 utilization.

Nanostructured Materials for Photothermal Carbon Dioxide Hydrogenation: Regulating Solar Utilization and Catalytic Performance.

The continuous temperature rise has raised global concerns about CO2 emissions. As the country with the largest CO2 emissions, China is facing the challenge of achieving large CO2 emission reductions (or even net-zero CO2 emissions) in a short period. With the strong support and encouragement of the Chinese government, technological breakthroughs and practical applications of carbon capture, utilization, and storage (CCUS) are being aggressively pursued, and some outstanding accomplishments have been realized. Based on the numerous information from a wide variety of sources including publications and news reports only available in Chinese, this paper highlights the latest CCUS progress in China after 2019 by providing an overview of known technologies and typical projects, aiming to provide theoretical and practical guidance for achieving net-zero CO2 emissions in the future.

/pdf/a-review-of-recent-progress-of-carbon-capture-utilization-3cl8ptka.pdf

A Review of Recent Progress of Carbon Capture, Utilization, and Storage (CCUS) in China

This study presents laser stripe center extraction algorithm for desktop-level 3D laser scanners. The laser stripe center extraction accuracy is an important factor affecting 3D scanning result. Desktop-level devices should have adaptability of a wide range of scanning objects. In this paper, laser stripe energy distribution characteristics with different laser stripe width, ambient light, materials and colors are obtained by experiments. Experiment results show that waveforms of bright spot, low brightness stripe and stripe with large width are complex or easily disturbed, so the center extraction algorithm of them are studied. The extraction effects of extremum method, gradient method and gray centroid method under different conditions are compared. Based on traditional grayscale value, a weighted grayscale value is proposed to extract laser stripe center. Standard deviations of extracted pixel position and fitting pixel position are calculated by different method with different weighted grayscale value. For different conditions, especially for different ambient light intensity, weight matrix plays an important role to extraction result.

/pdf/research-on-laser-stripe-characteristics-and-center-4q4gbdtjbr.pdf

Research on laser stripe characteristics and center extraction algorithm for desktop laser scanner

Heterogeneous Catalysts toward CO2 Hydrogenation for Sustainable Carbon Cycle

Abstract The conversion of CO 2 by renewable power-generated hydrogen is a promising approach to a sustainable production of long-chain olefins (C 4+ = ) which are currently produced from petroleum resources. The decentralized small-scale electrolysis for hydrogen generation requires the operation of CO 2 hydrogenation in ambient-pressure units to match the manufacturing scales and flexible on-demand production. Herein, we report a Cu-Fe catalyst which is operated under ambient pressure with comparable C 4+ = selectivity (66.9%) to that of the state-of-the-art catalysts (66.8%) optimized under high pressure (35 bar). The catalyst is composed of copper, iron oxides, and iron carbides. Iron oxides enable reverse-water-gas-shift to produce CO. The synergy of carbide path over iron carbides and CO insertion path over interfacial sites between copper and iron carbides leads to efficient C-C coupling into C 4+ = . This work contributes to the development of small-scale low-pressure devices for CO 2 hydrogenation compatible with sustainable hydrogen production. 

/pdf/ambient-pressure-hydrogenation-of-co2-into-long-chain-3eps7idr.pdf

Ambient-pressure hydrogenation of CO2 into long-chain olefins

Phosphorus Absorption and Release in Biofilm Sequencing Batch Reactor: The Combined Action of Cells and Extracellular Polymeric Substances and the Characteristics of Polymer Metabolism

A 360-degree realistic 3D image display system based on direct light scanning method, so-called Holo-Table has been introduced in this paper. High-density directional continuous 3D motion images can be displayed easily with only one spatial light modulator. Using the holographic screen as the beam deflector, 360-degree full horizontal viewing angle was achieved. As an accompany part of the system, CMOS camera based image acquisition platform was built to feed the display engine, which can take a full 360-degree continuous imaging of the sample at the center. Customized image processing techniques such as scaling, rotation, format transformation were also developed and embedded into the system control software platform. In the end several samples were imaged to demonstrate the capability of our system.

Yue Chen

Papers

Ambient-pressure hydrogenation of CO2 into long-chain olefins

Phosphorus Absorption and Release in Biofilm Sequencing Batch Reactor: The Combined Action of Cells and Extracellular Polymeric Substances and the Characteristics of Polymer Metabolism

360 degree realistic 3D image display and image processing from real objects