Comparative Analysis of Green Solvent Effects in Catalytic Reactions Across Regions

Thesis Abstract

This study addresses a critical challenge in modern catalysis the environmental and regional variability in the performance of green solvents and their influence on catalytic efficiency, selectivity, and sustainability metrics. Despite the growing emphasis on green chemistry, comparative insights across regions remain fragmented due to divergent solvent classifications, regulatory frameworks, and industrial practices. The aim is to systematically evaluate how green solvent systems affect catalytic reactions across distinct regional contexts, with a focus on reaction efficiency, product selectivity, lifecycle emissions, and process feasibility. Specific objectives are (1) to compare solvent performance in representative catalytic reactions—including esterification, hydrogenation, and oxidation—using environmentally benign solvents such as bio-based alcohols, deep eutectic solvents, and supercritical CO2; (2) to quantify regional variations in solvent influence on turnover frequency (TOF), enantioselectivity, and catalyst longevity; (3) to assess lifecycle environmental impacts (global warming potential, water footprint) and economic viability across regions; (4) to identify underlying factors driving regional differences, including regulatory constraints, solvent supply chains, and lab-to-pilot scale transitions; and (5) to propose region-specific best-practice guidelines for solvent selection in catalytic processes. The methodology adopts a cross-regional, mixed-methods design combining experimental catalysis with quantitative lifecycle assessment and qualitative stakeholder insights. The population comprises established catalytic systems sourced from laboratories and pilot plants in three representative regions North America, Europe, and Asia-Pacific. A stratified sample of 12 catalytic reactions will be selected, with four reactions per region, incorporating homogeneous and heterogeneous catalysts. Data collection employs standardized reaction condition matrices, high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) for product analysis, and calorimetry for reaction energetics. Lifecycle assessment (LCA) is conducted following ISO 14040/44 standards, integrating inventory data from regional supply chains and using SimaPro for impact assessment. Additional qualitative data are gathered through semi-structured interviews with 18 process engineers and regulatory experts to elucidate contextual factors affecting solvent choice and implementation. The primary data analytic approach includes factorial ANOVA to test the effects of solvent type and region on TOF, selectivity, and energy consumption, complemented by multivariate regression modeling to identify predictors of catalyst deactivation. LCA results are analyzed via menu-based, region-specific impact pathways, and sensitivity analyses are performed to assess data uncertainties. Thematic analysis of interview transcripts will be conducted to extract perceived barriers and enablers, mapped to the consolidated theoretical framework. Expected findings include (i) statistically significant regional differences in catalytic performance linked to solvent properties such as polarity, viscosity, and hydrogen-bonding capacity; (ii) variation in environmental and economic metrics across regions, with certain green solvents offering superior cradle-to-gate sustainability in some regions due to cleaner supply chains; (iii) identification of solvent–catalyst compatibility patterns that optimize turnover and selectivity while minimizing energy input and catalyst degradation; and (iv) robust interaction effects indicating that the benefits of green solvents are contingent on regional regulatory and logistical contexts. The study contributes to knowledge by bridging chemistry and regional sustainability science, offering a systematic, data-driven framework to evaluate green solvents in catalysis beyond single-region assessments. It provides a decision-support toolkit incorporating experimental performance data, LCA results, and stakeholder perspectives to guide region-specific solvent selection and process design. The main conclusion anticipated is that green solvent choice exerts region-dependent effects on catalytic performance and sustainability, necessitating tailored solvent selection strategies rather than universal prescriptions. Recommendations include developing regional solvent portfolios aligned with local supply chains and policy landscapes, adopting decision frameworks that integrate performance and environmental metrics, and prioritizing catalytic systems with broad solvent tolerance to enhance transferability across regions.