We studied the possibility of converting waste toilet paper (WTP) into electricity. WTP is a waste stream with continuous availability and negative cost, but it is difficult to handle, as it contains fecal matter. The process we explored had two stages: WTP gasification followed by direct conversion into electricity in a high-temperature solid-oxide fuel cell (SOFC). The process was studied on a 10 ktpa scale by using real-life parameter values obtained from industrial sources. We presented the basic system design, as well as its electricity yield and overall efficiency on the basis of detailed mass- and energy-balance calculations. By explorative technoeconomic analysis and sensitivity analysis, we found an electric efficiency of 57 %, which is similar to that of a natural gas combined cycle plant. The levelized cost of electricity (LCOE) was 20.3 ¢ kWh−1, which is comparable at present to that of residential photovoltaic installations. The system's capital costs are relatively high, mainly as a result of SOFC investment costs, but we expect these costs to decrease as the market of cells develops. The operating costs are relatively low, partly thanks to the high thermodynamic efficiency (≈70 %). Currently, the fuel costs are negative (because we use waste as a raw material), yet this could change if the value of WTP would increase as a result of this process. Learning effects could make the system more competitive in the future with an LCOE of approximately 11 ¢ kWh−1.@en

MXenes are a new family of 2D carbides or nitrides that have attracted attention due to their layered structure, tunable surface groups and high electrical conductivity. Here, we report for the first time that the Ti2CTx MXene catalyses the selective oxidative dehydrogenation of n-butane to butenes and 1,3-butadiene. This catalyst showed higher intrinsic activity compared to a commercial TiC and TiO2 samples in terms of C4 olefin formation rate. We propose that the stabilisation of structural vacancies and the change in composition (from a carbide to a mixed phase oxide) in the MXene causes its higher catalytic activity. These vacancies can lead to a higher concentration of unpaired electrons in the MXene-derived material, enhancing its nucleophilic properties and favouring the production of olefins.@en

Immobilizing molecular catalysts on electrodes is vital for electrochemical applications. However, creating robust electrode-catalyst interactions while maintaining good catalytic performance and rapid electron transfer is challenging. Here, without introducing any foreign elements, we show a bottom-up synthetic approach of constructing the conjugated C−C bond between the commercial Vulcan carbon electrode and an organometallic catalyst. Characterization results from FTIR, XPS, aberration-corrected TEM and EPR confirmed the successful and uniform heterogenization of the complex. The synthesized Vulcan-LN4−Co catalyst is highly active and selective in the oxygen reduction reaction in neutral media, showing an 80 % hydrogen peroxide selectivity and a 0.72 V (vs. RHE) onset potential which significantly outperformed the homogenous counterpart. Based on single-crystal XRD and NMR data, we built a model for density functional theory calculations which showed a nearly optimal binding energy for the *OOH intermediate. Our results show that the direct conjugated C−C bonding is an effective approach for heterogenizing molecular catalysts on carbon, opening new opportunities for employing molecular catalysts in electrochemical applications.@en

MAX (Mn+1AXn) phases are layered carbides or nitrides with a high thermal and mechanical bulk stability. Recently, it was shown that their surface structure can be modified to form a thin non-stoichiometric oxide layer, which can catalyze the oxidative dehydrogenation of butane. Here, the use of a Ti2AlC MAX phase as a support for cobalt oxide was explored for the dry reforming of butane with CO2, comparing this new catalyst to more traditional materials. The catalyst was active and selective to synthesis gas. Although the surface structure changed during the reaction, the activity remained stable. Under the same conditions, a titania-supported cobalt oxide catalyst gave low activity and stability due to the agglomeration of cobalt oxide particles. The Co3O4/Al2O3 catalyst was active, but the acidic surface led to a faster deactivation. The less acidic surface of the Ti2AlC was better at inhibiting coke formation. Thanks to their thermal stability and acid-base properties, MAX phases are promising supports for CO2 conversion reactions.@en