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To address the energy and environmental issues related to the use of traditional fossil fuels, the thermal utilization of low-grade solid fuels such as low-rank coal, biomass, and municipal solid waste has gradually attracted much attention. During the combustion of the low-grade solid fuels, one of the major operation problems is the fireside corrosion on heat transfer tubes, which easily causes the frequent replacement of tubes and shutdown of boilers, largely reducing the energy and economic performances. In this review, the causes and mechanisms of corrosion were first clarified to provide a basis for mitigating the losses induced by the fireside corrosion, followed by the introduction of the preparation and properties of coatings, which show great potential to resist the invasion of corrosive species by attaching the reinforced surface to the tubes. To demonstrate the feasibility of the coating for hightemperature corrosion resistance, 94 kinds of coatings in more than 60 literature contributions were statistically analyzed. It was found that over 90% of anticorrosion coatings were prepared from thermal spraying techniques, and approximately three-quarters of the anticorrosion coatings were made of NiCr-based alloys. Many methods were reported to evaluate the corrosion resistance of coatings in literature, including mass gain/loss method, ash deposition method, contact angle method, and ash adhesion method. As for exploring the anticorrosion mechanisms of coatings, it was found that the protection was achieved by the formation of dense oxide scale, such as Cr 2 O 3 , NiO, MoO 2 , and so on. Furthermore, the application status of coatings in power plants was also summarized. According to the pilot-scale tests listed in literature, the obvious similarity is that the adopted technologies were mainly High velocity oxy-fuel (HVOF) spraying or cold spraying techniques, with almost all of the coated materials being NiCr-based alloys as well as a small portion of Fe/Co-based alloys. This indicates that the NiCr-based coatings prepared by HVOF spraying technique have been widely applied in power plants. In order to promote the large-scale application of anticorrosion coatings, it is prospective to focus on several key research aspects: (1) predicting the corrosion conditions from fuel compositions, (2) developing costeffective coatings, (3) establishing the systematic evaluation methods by laboratory tests, (4) achieving in-depth understanding of the anticorrosion mechanisms, and (5) conducting a comprehensive economic analysis.

Silicon is considered as one of the most promising alternatives to the graphite anode for lithium-ion batteries due to its high theoretical capacity (4200 mAh g−1). However, its fragile solid electrolyte interphase cannot tolerate the large volume changes of bare silicon induced by the lithium insertion and extraction, resulting in low Coulombic efficiency. In previous reports, a yolk-shell design, such as Si@void@C, in which the well-defined space allows the silicon particles to expand freely without breaking the outer carbon shells, can effectively improve the Columbic efficiency. Here, we design a pomegranate-like silicon-based anodes self-assembled by the hollow-structured Si/void@C nanoparticles, in which silicon and some voids are together sealed in the outer carbon shells, by the magnesiothermic reduction of the colloidal SiO2@PEI nanospheres prepared by the hydrolysis of the tetraethoxysilane under the catalytic effect of polyetherimide (PEI). Due to the tolerance of the presealed void in the carbon shells of the primary hollow-structured Si/void@C nanoparticles, the prepared pomegranate-like silicon-based anodes deliver a high reversible capacity of 1615 mAh g−1 at 0.1 C and long cycle life of 73.5% capacity retention at 2 C after 500 cycles, as well as high Coulombic efficiency of 99%.

Cobalt-based alloy coatings and WC-Co-based ceramic–metal (cermet) coatings have been widely used because of their desirable mechanical properties and corrosion resistance. In this work, the influence of Co content on the microstructure, mechanical properties and cavitation erosion (CE) resistance were investigated. A cobalt-based alloy coating, a WC-12Co coating, and a WC-17Co cermet coating were deposited by high-velocity oxygen fuel (HVOF) spraying on 1Cr18Ni9Ti substrates. Results indicate that the cobalt-based alloy coating had the largest surface roughness because surface-bonded particles of lower plastic deformation were flattened. The existence of WC particles had led to an increase in hardness and improved the fracture toughness due to inhibit crack propagation. The pore appeared at the interface between WC particles, and the matrix phase had introduced an increase in porosity. With the increase in Co content, the cohesion between matrix friction and WC particles increased and then decreased the porosity (from 0.99% to 0.84%) and surface roughness (Ra from 4.49 to 2.47 μm). It can be concluded that the hardness had decreased (from 1181 to 1120 HV0.3) with a decrease in WC hard phase content. On the contrary, the fracture toughness increased (from 4.57 to 4.64 MPa∙m1/2) due to higher energy absorption in the matrix phase. The WC-12Co and WC-17Co coatings with higher hardness and fracture toughness exhibited better CE resistance than the cobalt-based alloy coating, increasing more than 20% and 16%, respectively. Especially, the WC-12Co coating possessed the best CE resistance and is expected to be applicable in the hydraulic machineries.

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CaTiO3 tetragonal microrods with vertical V-type holes along the [010] direction are synthesized successfully and their growth mechanism is discussed.

Furan is a typical heterocyclic compound in pyrolytic tar and has a strong tendency of coke deposition in thermochemical conversion, leading to catalyst deactivation for tar upgrading. The present study proposed a promising method for furan cracking and reforming using molten alkali carbonates (Li 2 CO 3 −Na 2 CO 3 −K 2 CO 3 ). The results showed that a little gas was generated in the conversion process and CO dominated the gas species. In comparison to the experiment under salt-free conditions, the decarbonylation of furan in molten salt conversion was strengthened and oxygen could be removed as H 2 O into the liquid products. Under the catalysis of alkali metal cations, the conversion of furan to aromatic compounds was promoted at each temperature. Moreover, excess CO 2 enhanced the reverse water−gas reaction, resulting in the consumption of H 2 and the increase of CO in gaseous products. In addition, coke produced in molten salts was of higher reactivity and could hardly affect the stability of the molten salt system. On the basis of the good thermal conversion behavior as well as anticoking performance of molten carbonates, these findings offer a new way for the proper reforming and upgrading of furan through molten salt thermal treatment.