Ranking of Heterogeneous Catalysts Metals by Their Greenness

Abstract

Catalysis is a very important process in industry and laboratory practices, especially from the point of green chemistry principles. However, the eco-friendly character of heterogeneous catalysts containing transition-metal components has not yet been evaluated. Therefore, we performed a comprehensive assessment of 18 heterogeneous metal catalysts (Pd, Pt, V, Co, Ni, Mo, Ru, Mn, Au, Cu, Cd, Zr, Fe, Rh, Ir, Sn, Zn, Ag) using a multicriteria decision analysis approach. The ranking of alternatives according to relevant criteria, such as the toxicity of pure metals and metal salts toward fish, Daphnia magna, and algae/plants, metal toxicity toward rats via ingestion, carcinogenicity, the endangerment degree of metals, the boiling point and energy for atom detachment (estimated as metal–metal bond strength in diatomic transition-metal units), and the classification of elemental impurities according to the International Conference on Harmonization, and their degree of importance are presented. Life cycle assessment (LCA)-related parameters of metals have been also included. The assessment showed ruthenium, iron, and molybdenum as the most favorable alternatives, in contrast to nickel, cobalt, and rhodium. Results of environmental evaluation strictly depend on the chosen scenario of assessment, in terms of toxicity, endangered elements, or LCA. Sensitivity analyses toward variations in input data and applied weights prove that the results are reliable. Multicriteria decision analysis can be successfully applied in metal catalyst evaluation for particular case studies of different reactions.

Novel magnetic propylsulfonic acid-anchored isocyanurate-based periodic mesoporous organosilica (Iron oxide@PMO-ICS-PrSO3H) as a highly efficient and reusable nanoreactor for the sustainable synthesis of imidazopyrimidine derivatives

“…The obtained results from optimization experiments illustrated that both the catalyst loading and temperature strongly affect the reaction progress which have been summarized in Table 1. Indeed, only a trace amount of the desired product, 12-(4-chlorophenyl)-3,3-dimethyl-3,4,5,12tetrahydrobenzo [4,5] www.nature.com/scientificreports/ www.nature.com/scientificreports/ deligh, the use of Iron oxide@PMO-ICS-PrSO 3 H (1) at 7 mg loading enhanced significantly the yield of the desired product 6a under the same conditions ( Table 1, entry 2). Increasing of the catalyst loading to 10 mg (Iron oxide@PMO-ICS-PrSO 3 H, 1) afforded higher yield of the desired product in shorter reaction time (entry 3).…”

Pd on Nanodiamond/Graphene in Hydrogenation of Propyne with Parahydrogen

“…In recent decades, much progress has been made with enhancing Pd-based catalyst selectivity in acetylene hydrogenation by controlling the particle shape/morphology, the introduction of both inorganic and organic modifiers, and the addition of a second metal with the formation of bimetallic/intermetallic catalysts . However, the green chemistry principles prompt researchers to search for more efficient catalysts with reduced amounts of the active metal . A new class of catalysts, single-atom catalysts (SACs), has been actively studied in this context. − SACs feature atomically dispersed metal atoms anchored onto a support material, so the metal utilization can approach 100%, which is especially important in the case of noble metals .…”

“…4 However, the green chemistry principles prompt researchers to search for more efficient catalysts with reduced amounts of the active metal. 5 A new class of catalysts, single-atom catalysts (SACs), has been actively studied in this context. 6−11 SACs feature atomically dispersed metal atoms anchored onto a support material, so the metal utilization can approach 100%, which is especially important in the case of noble metals.…”

2D and 3D Ruthenium Nanoparticle Covalent Assemblies for Phenyl Acetylene Hydrogenation

“…[ 40 ] From an environmental point of view and cost, it has been shown that ruthenium is a greener heterogeneous catalyst compared to other noble metals. [ 41 ] Surprisingly, even if colloidal Ru NP are usually highly efficient (selective) hydrogenation catalysts, [ 42 ] reports on the application of Ru NP for this specific catalytic reduction are relatively scarce. [ 16a,43 ] We recently evidenced that for 3D Ru NP assemblies produced from polymantane ligands, the Ru NP interparticle distance (steric effect) and electronic effects control the catalyst activity and selectivity.…”