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SiC is one of the most important ceramics at present due to its excellent properties and wide range of applications. The industrial production method, known as the Acheson method, has not changed in 125 years. Because the synthesis method in the laboratory is completely different, laboratory optimisation may not be extrapolated to the industrial level. In the present study, the results at the industrial level and at the laboratory level of the synthesis of SiC are compared. These results show that it is necessary to make a more detailed analysis of the coke than the traditional one; therefore, the Optical Texture Index (OTI) should be included, as well as the analysis of the metals that form the ashes. It has been found that the main influencing factors are OTI and the presence of Fe and Ni in the ashes. It has been determined that the higher the OTI, as well as the Fe and Ni content, the better the results obtained. Therefore, the use of regular coke is recommended in the industrial synthesis of SiC. The authors acknowledge the financial support given by the “Ministerio de Ciencia e innovación” through the project PID2020-116998RB-I00 and the “Generalitat Valenciana” for the projects CIPROM/2021/022 and PRTR-C17.I1.

Metal–organic frameworks (MOFs) are porous hybrid materials with countless potential applications. Most of these rely on their porous structure, tunable composition, and the possibility of incorporating and expanding their functions. Although functionalization of the inner surface of MOF crystals has received considerable attention in recent years, methods to functionalize selectively the outer crystal surface of MOFs are developed to a lesser extent, despite their importance. This article summarizes different types of post-synthetic modifications and possible applications of modified materials such as: catalysis, adsorption, drug delivery, mixed matrix membranes, and stabilization of porous liquids. The authors acknowledge financial support by Ministerio de Ciencia e Innovación (PID2020-116998RB-I00), Ministerio de Educación y Formación Profesional (PRX21/00407), Conselleria de Innovacion, Universidades, Ciencia y Sociedad Digital (CIPROM/2021/022), and the King Abdullah University of Science and Technology (KAUST). This study forms part of the Advanced Materials programme and was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and by Generalitat Valenciana.

One way to exploit CO2 is to use it as a feedstock for the production of cyclic carbonates via its reaction with organic epoxides. As far as we know, there is still no heterogeneous catalyst that accelerates the reaction in a selective, efficient and industrially usable way. Cobalt and zinc-based zeolitic imidazole frameworks (ZIFs) have been explored as heterogeneous catalysts for this reaction. In particular, we have prepared ZIF-8 and ZIF-67 catalysts, which have been modified by partial replacement of 2-methylimidazole by 1,2,4-triazole, in order to introduce uncoordinated nitrogen groups with the metal. The catalysts have shown very good catalytic performance, within the best of the heterogeneous catalysts tested in the cycloaddition of CO2 with epichlorohydrin. The catalytic activity is due ultimately to defects on the outer surface of the crystal, and varies in the order of ZIF-67-m > ZIF-67 > ZiF-8-m = ZIF-8. Notably, reactions take place under mild reaction conditions and without the use of co-catalysts. The authors acknowledge financial support by MINECO (Spain) through the projects MAT2017-86992-R and CTQ2017-88171-P, “Ministerio de Ciencia e innovación” (PID2020-116998RB-I00), Ministerio de Educación y Formación Profesional (PRX21/00407), and Conselleria de Innovacion, Universidades, Ciencia y Sociedad Digital (CIPROM/2021/022, MFA/2022/048).

One way to exploit CO

MIL-100(Fe) is a metal–organic framework (MOF) characterized by the presence of Lewis acid and Fe(II/III) redox sites. In this work, different synthesis methods for the preparation of MIL-100(Fe) are studied. Depending on the source of fluorine, different phases can be obtained: MIL-100(Fe) and an Fe trimesate with unknown structure which we call Fe(BTC). These materials were characterized using numerous techniques and applied in the reaction of CO2 cycloaddition with epichlorohydrin, a reaction catalyzed by Lewis acid sites. It was observed that samples with more Fe(BTC) phase were more active in the reaction. However, all samples, under reaction conditions, transformed into a less active phase. The authors acknowledge financial support by MINECO (Spain) through the project MAT2017-86992-R, “Ministerio de Ciencia e innovación” (PID2020-116998RB-I00), Ministerio de Educación y Formación Profesional (PRX21/00407), and Conselleria de Innovacion, Universidades, Ciencia y Sociedad Digital (CIPROM/2021/022).

Nowadays one of the biggest challenges for carbon materials is their use in CO2 capture and their use as electrocatalysts in the oxygen reduction reaction (ORR). In both cases, it is necessary to dope the carbon with nitrogen species. Conventional methods to prepare nitrogen doped carbons such as melamine carbonization or NH3 treatment generate nitrogen doped carbons with insufficient nitrogen content. In the present research, a series of activated carbons derived from MOFs (ZIF-8, ZIF-67) are presented. Activated carbons have been prepared in a single step, by pyrolysis of the MOF in an inert atmosphere, between 600 and 1000 °C. The carbons have a nitrogen content up to 20 at.% and a surface area up to 1000 m2/g. The presence of this nitrogen as pyridine or pyrrolic groups, and as quaternary nitrogen are responsible for the great adsorption capacity of CO2, especially the first two. The presence of Zn and Co generates very different carbonaceous structures. Zn generates a greater porosity development, which makes the doped carbons ideal for CO2 capture. Co generates more graphitized doped carbons, which make them suitable for their use in electrochemistry. Authors acknowledge financial support by MINECO (Spain) through the project MAT2017-86992-R and “Ministerio de Ciencia e Innovación” (PID2020-116998RB-I00).

We studied the catalytic hydrogenation of CO2 to methane using nickel-niobia composite catalysts. Catalysts containing 10–70 wt% Ni were synthesized by wet impregnation and tested for CO2 hydrogenation in a flow reactor. 40 wt% was found to be the optimum Ni loading, which resulted in CO2 conversion of 81% at 325 °C. We also calcined the Nb2O5 support at different temperatures to study the influence of calcination temperature on the catalytic performance. 40 wt% Ni loaded on Nb2O5, which was calcined at 700 °C gave higher methanation activity (91% conversion of CO2). Time on stream study for 50 h showed a stable activity and selectivity; thus confirming the scope for practical application. E.S.G. and N.R.S acknowledge the financial support from NOW CAPITA project (732.013.002). ASE acknowledges the financial support from the MINECO projects MAT-2013-45008-P and MAT2016-81732-ERC. EVRF gratefully acknowledge support from MINECO for his Ramón y Cajal grant (RyC-2012-11427) and University of Alicante for the project GRE-13-31. Generalitat Valenciana is also acknowledged for financial support (PROMETEOII/ 2014/004).