{"id":233596,"date":"2026-03-18T23:12:15","date_gmt":"2026-03-19T04:12:15","guid":{"rendered":"https:\/\/lifeboat.com\/blog\/2026\/03\/the-effect-of-exogenous-acid-identity-on-iron-tetraphenylporphyrin-catalyzed-co2-reductionclick-to-copy-article-linkarticle-link-copied"},"modified":"2026-03-18T23:12:15","modified_gmt":"2026-03-19T04:12:15","slug":"the-effect-of-exogenous-acid-identity-on-iron-tetraphenylporphyrin-catalyzed-co2-reductionclick-to-copy-article-linkarticle-link-copied","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2026\/03\/the-effect-of-exogenous-acid-identity-on-iron-tetraphenylporphyrin-catalyzed-co2-reductionclick-to-copy-article-linkarticle-link-copied","title":{"rendered":"The Effect of Exogenous Acid Identity on Iron Tetraphenylporphyrin-Catalyzed CO2 ReductionClick to copy article linkArticle link copied!"},"content":{"rendered":"<p><a class=\"aligncenter blog-photo\" href=\"https:\/\/lifeboat.com\/blog.images\/the-effect-of-exogenous-acid-identity-on-iron-tetraphenylporphyrin-catalyzed-co2-reductionclick-to-copy-article-linkarticle-link-copied2.jpg\"><\/a><\/p>\n<p>\u2018The Effect of Exogenous Acid Identity on Iron Tetraphenylporphyrin-Catalyzed CO2 Reduction\u2019 from Inorganic Chemistry is currently free to read as an ACSEditorsChoice.<\/p>\n<p>\ud83d\udcd6 Read the article.<\/p>\n<hr>\n<p>Iron tetraphenylporphyrin (FeTPP) is a privileged electrocatalyst for the 2e\u2013\/2H+ reduction of CO2 to CO. FeTPP-catalyzed CO2 reduction typically employs phenol as an exogenous acid to promote the rate-limiting proton-coupled electron transfer. Beyond the observation that catalytic rates increase with decreasing pKa, the effects of acid identity on reaction kinetics are largely unexplored. Herein, we report rates of FeTPP-catalyzed CO2 reduction with structurally diverse O\u2013H, N\u2013H, and C\u2013H acids. While many of these acids follow the expected Br\u00f8nsted relationship, there are several notable exceptions: the fluorinated alcohols hexafluoroisopropanol (log(kcat) = 4.54) and 2,2,2-trifluoroethanol (log(kcat) = 3.55)\u2500and the N\u2013H acid imidazole (log(kcat) = 4.41)\u2500display catalytic rates that are several times greater than rates obtained with similarly acidic phenols. Amides with pKas 19 (in dimethyl sulfoxide) display similar activity as comparably acidic O\u2013H acids, while rates obtained with less acidic amides are \u223c2 orders of magnitude slower than O\u2013H donors of similar pKa. Each C\u2013H acid affords poor activity. An Eyring analysis suggests that acids enforcing less ordered transition states afford superior kinetics. This study reveals that acid pKa is only one relevant parameter for altering catalytic rates, and judicious selection of the acid is crucial for enhancing catalytic rates.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u2018The Effect of Exogenous Acid Identity on Iron Tetraphenylporphyrin-Catalyzed CO2 Reduction\u2019 from Inorganic Chemistry is currently free to read as an ACSEditorsChoice. \ud83d\udcd6 Read the article. Iron tetraphenylporphyrin (FeTPP) is a privileged electrocatalyst for the 2e\u2013\/2H+ reduction of CO2 to CO. FeTPP-catalyzed CO2 reduction typically employs phenol as an exogenous acid to promote the rate-limiting [\u2026]<\/p>\n","protected":false},"author":662,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19,17],"tags":[],"class_list":["post-233596","post","type-post","status-publish","format-standard","hentry","category-chemistry","category-sustainability"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/233596","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/662"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=233596"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/233596\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=233596"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=233596"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=233596"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}