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CO2 hydrogenation to methane (also known as "CO2 methanation") is an important way to achieve the goal of carbon neutralization. CeO2 is considered as one of the most important catalyst supports because of its abundant surface oxygen vacancies and excellent oxygen storage capacity. Transition metal Ni is also widely studied because of its excellent catalytic performance and low price. The Ni/CeO2-based catalysts formed by the combination of CeO2 and metal Ni show good application prospects in CO2 methanation. The reaction mechanisms of Ni/CeO2-based catalysts for CO2 methanation were summarized and the preparation methods of Ni/CeO2-based catalysts were introduced, and the key parameters affecting catalytic performance of CO2 methanation such as the characteristics of active centers, properties of supports, types of additives and metal-support interactions were summarized, and the catalytic performances of Ni/CeO2-based catalysts were also summarized. It is found that by modifying Ni/CeO2-based catalysts, the catalytic performances and product selectivities of Ni/CeO2-based catalysts for CO2 methanation can be regulated, which can provide new ideas for improving their catalytic performances of CO2 methanation. [ABSTRACT FROM AUTHOR]

Real-time localization is an important mission for self-driving cars and it is difficult to achieve precise pose information in dynamic environments. In this paper, a novel localization method is proposed to estimate the pose of self-driving cars using a 3D-LiDAR sensor. First, the multi-frame curb features and laser intensity features are extracted. Meanwhile, based on the high-precision curb map generated offline, obstacles on road are detected using region segmentation methods and their features are removed. Furthermore, a map-matching method is proposed to match the features to the map, a robust iterative closest point algorithm is utilized to deal with curb features along with a probability search method dealing with intensity features. Finally, two separate Kalman filters are used to fuse the low-cost global positioning systems and map-matching results. Both offline and online experiments are carried out in dynamic environments and the results demonstrate the accuracy and robustness of the proposed method. [ABSTRACT FROM AUTHOR]

We report the synthesis, characterization, and reactivities of two stable NiIII N‐confused porphyrin (NCP) complexes. Metalation of 3‐OEt NCP 1 with NiCl2 ⋅ 6H2O in CHCl3/EtOH gave 3‐OEt NiII NCP 3 initially, which was easily oxidized in air to form the NiIII complex of NCP inner C‐oxide 4. Bis‐ethoxy‐modified NiIII complex 5 was synthesized by oxidation of 3 with PIFA in ethanol and CHCl3. The structures of 4 and 5 were determined by single‐crystal X‐ray diffraction analysis. An unusually long NiIII−C bond (2.170(9) Å) was observed in 4. The g‐factor (g>2.1) observed in the EPR spectra of 4 and 5 further confirmed that they are paramagnetic NiIII complexes. Comparative experiments showed that the 3‐ethoxy group plays an important role in the formation of 4 and 5. Reduction of 4 and 5 with NaBH4 regenerated complex 3. [ABSTRACT FROM AUTHOR]

Silicon dioxide (SiO 2 ) from rice husk can be extracted and be used as support for Ni-based catalysts. The impregnation method (IM) is usually used for preparing Ni/SiO 2 catalysts, but its catalytic activity in CO 2 hydrogenation to CH 4 remains unsatisfactory. In this work, we explored alternative preparation methods, using ammonia evaporation method (AEM) and hydrothermal method (HM) to prepare the catalysts. The results showed that the catalysts prepared by AEM and HM were significantly superior to that prepared by IM. Notably, the catalyst synthesized by AEM from sustainable silica exhibited the best performance, achieving 81.69 % CO 2 conversion and over 99 % methane selectivity at low reaction temperature of 300 °C. The characterization techniques indicate that the Ni/SiO 2 -AEM catalyst can form nickel phyllosilicate with lamellar structure, leading to better Ni dispersion and higher specific surface area. Furthermore, the results of in-situ DRIFTS have revealed the potential catalytic mechanism over Ni/SiO 2 catalysts, indicating that it involves pathways with both the CO* and HCOO* as the key intermediates., (© 2024 Wiley-VCH GmbH.)

We report the synthesis, characterization, and reactivities of two stable Ni III N-confused porphyrin (NCP) complexes. Metalation of 3-OEt NCP 1 with NiCl 2  ⋅ 6H 2 O in CHCl 3 /EtOH gave 3-OEt Ni II NCP 3 initially, which was easily oxidized in air to form the Ni III complex of NCP inner C-oxide 4. Bis-ethoxy-modified Ni III complex 5 was synthesized by oxidation of 3 with PIFA in ethanol and CHCl 3 . The structures of 4 and 5 were determined by single-crystal X-ray diffraction analysis. An unusually long Ni III -C bond (2.170(9) Å) was observed in 4. The g-factor (g>2.1) observed in the EPR spectra of 4 and 5 further confirmed that they are paramagnetic Ni III complexes. Comparative experiments showed that the 3-ethoxy group plays an important role in the formation of 4 and 5. Reduction of 4 and 5 with NaBH 4 regenerated complex 3., (© 2021 Wiley-VCH GmbH.)