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The production of carbon-rich hydrocarbons via CO 2 valorization is essential for the transition to renewable, non-fossil-fuel-based energy sources. However, most of the recent works in the state of the art are devoted to the formation of olefins and aromatics, ignoring the rest of the hydrocarbon commodities that, like propane, are essential to our economy. Hence, in this work, we have developed a highly active and selective PdZn/ZrO 2 +SAPO-34 multifunctional catalyst for the direct conversion of CO 2 to propane. Our multifunctional system displays a total selectivity to propane higher than 50% (with 20% CO, 6% C 1 , 13% C 2 , 10% C 4 , and 1% C 5 ) and a CO 2 conversion close to 40% at 350 °C, 50 bar, and 1500 mL g –1 h –1 . We attribute these results to the synergy between the intimately mixed PdZn/ZrO 2 and SAPO-34 components that shifts the overall reaction equilibrium, boosting CO 2 conversion and minimizing CO selectivity. Comparison to a PdZn/ZrO 2 +ZSM-5 system showed that propane selectivity is further boosted by the topology of SAPO-34. The presence of Pd in the catalyst drives paraffin production via hydrogenation, with more than 99.9% of the products being saturated hydrocarbons, offering very important advantages for the purification of the products.

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Polymer composite materials with hierarchical porous structure have been advancing in many different application fields due to excellent physico-chemical properties. However, their synthesis continues to be a highly energy-demanding and environmentally unfriendly process. This work reports a unique water based synthesis of monolithic 3D reduced graphene oxide (rGO) composite structures reinforced with poly(methyl methacrylate) polymer nanoparticles functionalized with epoxy functional groups. The method is based on reduction-induced self-assembly process performed at mild conditions. The textural properties and the surface chemistry of the monoliths were varied by changing the reaction conditions and quantity of added polymer to the structure. Moreover, the incorporation of the polymer into the structures improves the solvent resistance of the composites due to the formation of crosslinks between the polymer and the rGO. The monolithic composites were evaluated for selective capture of CO2. A balance between the specific surface area and the level of functionalization was found to be critical for obtaining high CO2 capacity and CO2/N2 selectivity. The polymer quantity affects the textural properties, thus lowering its amount the specific surface area and the amount of functional groups are higher. This affects positively the capacity for CO2 capture, thus, the maximum achieved was in the range 3.56–3.85 mmol/g at 1 atm and 25 °C.

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 Electrospinning allows the preparation of binderless lignin carbon fiber electrodes  Carbon fiber electrodes exhibit high surface area and well-dispersed Pt particles  Carbon electro-oxidation is affected by the O transfer between Pt and P  The stability and Pt accessibility make carbon electrodes suitable electrocatalysts  Electrodes with Pt show remarkable electrocatalytic response for alcohol oxidation ABSTRACT Lignin fibers, with and without phosphorus, and loaded with platinum have been prepared in a single step by electrospinning of lignin/ethanol/phosphoric acid/platinum acetylacetonate precursor solutions. Thermochemical treatments have been carried out to obtain lignin-based carbon fiber electrocatalysts. The electrospun lignin fibers were thermostabilized in air and carbonized at 900 ºC. The effect of phosphorus and platinum content on the porous texture, the surface chemistry and the oxidation/electro-oxidation A c c e p t e d M a n u s c r i p t 2 resistance have been studied. Phosphorus-containing carbon fibers develop a higher surface area (c.a.1200 m 2 g -1 ), exhibit a lower Pt particle size (2.1nm) and a better particle distribution than their counterpart without phosphorus (c.a.750 m 2 g -1 of surface area and 9.6nm Pt particle size). It has been proved that phosphorus improves the oxidation and electro-oxidation resistance of the fibers, avoiding their oxidation during the preparation thermal stages and is responsible of the generation of a microporous material with an unusual wide operational potential window (1.9V). An important Pt-P synergy has been observed in the oxygen transfer during the oxidation and electrooxidation of the fibers. The obtained carbon fibers can act directly as electrodes without any binder or conductivity promoter. The fibers with platinum have shown outstanding catalyst performance in the electro-oxidation of methanol and ethanol.

The transition from integrated petrochemical complexes toward decentralized chemical plants utilizing distributed feedstocks calls for simpler downstream unit operations. Less separation steps are attractive for future scenarios and provide an opportunity to design the next-generation catalysts, which function efficiently with effluent reactant mixtures. The methanol to olefins (MTO) reaction constitutes the second step in the conversion of CO 2 , CO, and H 2 to light olefins. We present a series of isomorphically substituted zeotype catalysts with the AEI topology (MAPO-18s, M = Si, Mg, Co, or Zn) and demonstrate the superior performance of the M(II)-substituted MAPO-18s in the conversion of MTO when tested at 350 °C and 20 bar with reactive feed mixtures consisting of CH 3 OH/CO/CO 2 /H 2 . Co-feeding high pressure H 2 with methanol improved the catalyst activity over time, but simultaneously led to the hydrogenation of olefins (olefin/paraffin ratio < 0.5). Co-feeding H 2 /CO/CO 2 /N 2 mixtures with methanol revealed an important, hitherto undisclosed effect of CO in hindering the hydrogenation of olefins over the Brønsted acid sites (BAS). This effect was confirmed by dedicated ethene hydrogenation studies in the absence and presence of CO co-feed. Assisted by spectroscopic investigations, we ascribe the favorable performance of M(II)APO-18 under co-feed conditions to the importance of the M(II) heteroatom in altering the polarity of the M–O bond, leading to stronger BAS. Comparing SAPO-18 and MgAPO-18 with BAS concentrations ranging between 0.2 and 0.4 mmol/g cat , the strength of the acidic site and not the density was found to be the main activity descriptor. MgAPO-18 yielded the highest activity and stability upon syngas co-feeding with methanol, demonstrating its potential to be a next-generation MTO catalyst.